Radio frequency identification tag delivery system

ABSTRACT

A system for operating a downhole tool includes a tag carrier; a RFID tag coupled with the tag carrier; and a control sub having a bore extending therethrough, the control sub comprising: an antenna located adjacent to the bore; and a stop for catching the tag carrier, wherein: the radio frequency identification tag is coupled with the tag carrier in relation to the stop and the antenna such that the radio frequency identification tag is aligned with the antenna when the tag carrier is caught in the stop, and the stop is operable to allow passage of the tag carrier through the stop after the tag carrier is caught by the stop.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of co-pending U.S. patent applicationSer. No. 15/153,421, filed May 12, 2016, which claims benefit of U.S.provisional patent application Ser. No. 62/161,344, filed May 14, 2015.Each of the aforementioned related patent applications is hereinincorporated by reference.

BACKGROUND OF THE DISCLOSURE Field of the Disclosure

The present disclosure generally relates to a radio frequencyidentification (RFID) tag delivery system.

Description of the Related Art

A wellbore is formed to access hydrocarbon-bearing formations (e.g.,crude oil and/or natural gas) or for geothermal power generation by theuse of drilling. Drilling is accomplished by utilizing a drill bit thatis mounted on the end of a drill string. To drill within the wellbore toa predetermined depth, the drill string is often rotated by a top driveon a drilling rig. After drilling to a predetermined depth, the drillstring and drill bit are removed and a string of casing is lowered intothe wellbore. An annulus is thus formed between the casing string andthe wellbore. The casing string is hung from the wellhead. A cementingoperation is then conducted in order to fill the annulus with cement.The casing string is cemented into the wellbore by circulating cementinto the annulus defined between the outer wall of the casing and theborehole. The combination of cement and casing strengthens the wellboreand facilitates the isolation of certain areas of the formation behindthe casing for the production of hydrocarbons.

Several downhole tools employed in the drilling and construction of thewellbore require selective downhole actuation, for example by droppingor pumping plugs or other devices down a bore of a tubular string (forexample, a drill, casing, conductor, liner, or work string) to land inthe downhole tool. The downhole tool is usually restrained in adeployment position by shearable fasteners which are released by theapplication of the fluid pressure against the landed plug, therebyshifting the tool to an activated position. This actuation methodsuffers from several deficiencies. A surge in wellbore pressure mayprematurely actuate the tool. It may also be desirable to return thedownhole tool to the deployment position once the tool has been used inthe activated position.

SUMMARY OF THE DISCLOSURE

The present disclosure generally relates to a radio frequencyidentification (RFID) tag delivery system. In one embodiment, a systemfor operating a downhole tool includes a tag carrier; a radio frequencyidentification tag coupled with the tag carrier; and a control subhaving a bore extending therethrough, the control sub comprising: anantenna located adjacent to the bore; and a stop for catching the tagcarrier, wherein: the radio frequency identification tag is coupled withthe tag carrier in relation to the stop and the antenna such that theradio frequency identification tag is aligned with the antenna when thetag carrier is caught in the stop, and the stop is operable to allowpassage of the tag carrier through the stop after the tag carrier iscaught by the stop.

In another embodiment, a method of operating a downhole tool includeslaunching a tag carrier carrying a radio frequency identification taginto a tubular string, wherein the tubular string comprises a controlsub and a downhole tool; pumping the tag carrier down the tubularstring; catching the tag carrier in a stop of the control sub; andtransmitting a command signal from the radio frequency identificationtag to an antenna of the control sub while the tag carrier is caught inthe stop.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the manner in which the above recited features of the presentdisclosure can be understood in detail, a more particular description ofthe disclosure, briefly summarized above, may be had by reference toembodiments, some of which are illustrated in the appended drawings. Itis to be noted, however, that the appended drawings illustrate onlytypical embodiments of this disclosure and are therefore not to beconsidered limiting of its scope, for the disclosure may admit to otherequally effective embodiments.

FIGS. 1, 2A, and 2B illustrate drilling of a wellbore using a drillingsystem having a tag delivery system, according to one embodiment of thepresent disclosure.

FIGS. 3A-3C illustrate a control sub and a circulation sub of thedrilling system.

FIGS. 4A, 4B, 4C, and 4D illustrate a tag carrier and an RFID tag of thetag delivery system. FIG. 4E illustrates an alternative active tag foruse with the tag delivery system, according to another embodiment of thepresent disclosure. FIG. 4F illustrates an alternative wirelessidentification and sensing platform tag for use with the tag deliverysystem, according to another embodiment of the present disclosure.

FIGS. 5A-5D illustrate operation of the tag delivery system.

FIG. 6A illustrates a cleanout operation being performed using thecirculation sub. FIG. 6B illustrates an arrival sensor for the tagdelivery system, according to another embodiment of the presentdisclosure. FIG. 6C illustrates an alternative arrival sensor for thetag delivery system, according to another embodiment of the presentdisclosure.

FIG. 7A illustrates an alternative circulation sub, according to anotherembodiment of the present disclosure.

FIGS. 7B-9B illustrate an inner string cementing operation performedusing the control sub and the alternative circulation sub.

FIG. 9C illustrates a cementing operation being performed using a firstalternative tag delivery system.

FIGS. 10A-10C illustrate a first alternative control sub, according toanother embodiment of the present disclosure.

FIGS. 11 and 12A-12D illustrate a second alternative tag delivery systemand operation thereof, according to another embodiment of the presentdisclosure. FIG. 13A illustrates an alternative tag carrier for use withthe second alternative tag delivery system, according to anotherembodiment of the present disclosure.

FIGS. 13B and 14A illustrate a second alternative control sub, accordingto another embodiment of the present disclosure. FIG. 14B illustratesanother second alternative control sub for operating a crossover tool,according to another embodiment of the present disclosure.

FIGS. 15A illustrates a liner deployment assembly having a thirdalternative control sub, according to another embodiment of the presentdisclosure. FIG. 15B illustrates operation of the liner deploymentassembly. FIG. 15C illustrates an accumulator for use with analternative liner deployment assembly, according to another embodimentof the present disclosure.

FIGS. 16A-16C illustrate the third alternative control sub.

FIGS. 17A-17D illustrate operation of the third alternative control sub.

FIGS. 18A and 18B illustrate a fourth alternative control sub, accordingto another embodiment of the present disclosure. FIG. 18C illustratesdelivery of the RFID tag to the fourth alternative control sub.

FIG. 19 illustrates a method of using a tag delivery system.

DETAILED DESCRIPTION

FIGS. 1, 2A, and 2B illustrate drilling of a wellbore using a drillingsystem 1 having a tag delivery system 2, according to one embodiment ofthe present disclosure. The drilling system 1 may include a drilling rig1 r, a fluid handling system 1 f, a pressure control assembly (PCA) 1 p,the tag delivery system 2, and a drill string 5. The drilling rig 1 rmay include a derrick 3 d, a floor 3 f, a top drive 4, and a hoist 12.The rig floor 3 f may have an opening through which the drill string 5extends downwardly into the PCA 1 p.

The drill string 5 may include a bottomhole assembly (BHA) 5 b and atubular string 5 s. The tubular string 5 s may include joints of drillpipe connected together, such as by threaded couplings. The BHA 5 b maybe connected to the tubular string 5 s, such as by threaded couplings.The BHA 5 b may include a control sub 6, a downhole tool, such ascirculation sub 7, a catcher 8, one or more drill collars 9, and a drillbit 10. Each BHA component 6-10 may be connected to adjacentcomponent(s), such as by threaded couplings. The drill bit 10 may berotated 11 r by the top drive 4 via the tubular string 5 s, and/or theBHA 5 b may further include a drilling motor (not shown) for rotatingthe drill bit. The BHA 5 b may further include an instrumentation sub(not shown), such as a measurement while drilling and/or a logging whiledrilling sub.

The tag delivery system 2 may include a swivel 13, a tag carrierlauncher 14, a tag carrier, a radio frequency identification (RFID) tag16, a control console 17, a hydraulic power unit (HPU) 18, and a stop19. The tag carrier may be a pump down plug, such as a dart 15. As usedherein, radio frequency identification (RFID) tag refers to tags thatcarry only identification information, as well as transponders thatcarry additional information, including pre-programmed command signals(that may include identification information). The RFID tag 16 may beattached to, disposed in or on, and/or otherwise coupled with the tagcarrier. The swivel 13 may include a housing torsionally connected tothe derrick 3 d, such as by bars, wire rope, or a bracket (not shown).The torsional connection may accommodate longitudinal movement of theswivel 13 relative to the derrick 3 d. The swivel 13 may further includea mandrel and bearings for supporting the housing from the mandrel whileaccommodating rotation 11 r of the mandrel. An upper end of the mandrelmay be connected to a quill of the top drive 4, such as by threadedcouplings. The housing may have an inlet in fluid communication with apassage formed through the mandrel and the swivel 13 may further includea seal assembly for isolating the inlet-passage communication. Themandrel passage may extend to an outlet for connection to a hydraulicconduit for operating a hydraulic actuator (e.g., a launcher actuator)of the tag carrier launcher 14. The swivel inlet may be in fluidcommunication with the HPU 18 operated by the control console 17. Thecontrol console 17 may be located on or near the floor 3 f, at anotherlocation on the drilling rig 1 r, or the control console 17 may belocated remotely from the drilling rig 1 r.

Alternatively, the swivel 13 may be omitted, and the launcher actuatormay be connected to a hydraulic swivel of the top drive 4.

The tag carrier launcher 14 may include a body, a deflector, a canister,a gate, an adapter, and the actuator. The body may be tubular and mayhave a bore therethrough. An upper end of the body may be connected to alower end of the swivel 13, such as by threaded couplings, and a lowerend of the body may be connected to a top of the launcher adapter, suchas by threaded couplings. The canister and deflector may each bedisposed in the body bore. The deflector may be connected to the swivelmandrel, such as by threaded couplings. The canister may belongitudinally movable relative to the body. The canister may be tubularand have ribs formed along and around an outer surface thereof. Bypasspassages may be formed between the ribs. Each canister may further havea landing shoulder formed in a lower end thereof for receipt by alanding shoulder of the launcher adapter. The launcher adapter may beconnected to a lower end of the body and a top of the tubular string 5s, such as by threaded couplings. The deflector may be operable todivert drilling fluid 20 d received from the swivel 13 away from a boreof the canister and toward the bypass passages.

Example darts 15, suitable for use as a tag carrier, is shownschematically in FIGS. 1 and 6A and in more detail in FIGS. 4A, 4B, 4C,and 5A. Dart 15 may be disposed in a bore of tubular string 5 s. The tagcarrier may have a catch element. For example, dart 15 may include aball stud 15 b. The ball stud 15 b may have a variety of shapes, such asgenerally spherical as seen in FIGS. 4A and 4B, or generally conical asseen in FIG. 4C. Dart 15 may also include finned seal and a mandrel 15m. The mandrel 15 m and ball stud 15 b may include a relatively stiffand nonconductive material, such as an engineering polymer or fiberreinforced composite. The finned seal may include one or more (fourshown in FIG. 5A) fins 15 f, coaxial with and disposed along an outersurface of the mandrel 15 m. The fins 15 f may be generally circular inshape (as shown in FIGS. 4A, 4B, and 4C), and the breadth of the finsmay vary (as seen in FIG. 4C). When disposed in the bore of the tubularstring 5 s, the fins 15 f may be compressed towards the mandrel 15 m (asshown in FIG. 5A). The non-compressed diameter of each of the fins 15 fmay vary. In some embodiments, each fin 15 f may have a non-compresseddiameter at least as large as the diameter of the bore of the controlsub 6. Each fin 15 f may include a relatively flexible material such asan elastomer or elastomeric copolymer. Fins 15 f may be molded or fittedto a gland (not shown) such that the fins may be stacked along themandrel 15 m. The fin glands may also include an engineering polymer orfiber reinforced composite. As may be recognized by those skilled in thepertinent art based on the teachings herein, the tag delivery system ofthe present disclosure may employ a variety of tag carrier launchers,and the tag carrier with catch element may take any of numerousdifferent shapes or configurations.

The mandrel 15 m may have a stacking shoulder (not shown) formed in anouter surface thereof for retaining the fin glands. The ball stud 15 bmay be connected to the mandrel 15 m, such as by a threaded connection,fasteners, and/or bonding. The ball stud 15 b may also have a stackingshoulder (not shown) formed in an outer surface thereof for retainingthe fin glands such that the finned seal is trapped between the stackingshoulders when the ball stud 15 b is connected to the mandrel 15 m. Anouter diameter of the ball stud 15 b may be greater than a diameter ofthe mandrel 15 m and less than an outer diameter of the largest of thefins 15 f (when fins 15 f are fully extended). An outer diameter of theball stud 15 b may be less than a diameter of the bore of the controlsub 6. The ball stud 15 b may be connected to a trailing end of themandrel 15 m. In some embodiments, the mandrel 15 m may have a noseformed at a leading end thereof. A receptacle may be formed in themandrel 15 m extending from the nose, and the RFID tag 16 may bedisposed in the receptacle (as seen in FIGS. 4A and 4C). The receptaclemay be centrally located within the dart 15. The RFID tag 16 may beretained in the receptacle, for example by a cap (not shown) releasablyconnected to the mandrel 15 m or by bonding. The RFID tag 16 wouldthereby be centralized in the bore of the tubular string 5 s, allowingconfidence in using only one RFID tag to transmit a command signal tothe control sub 6. In some embodiments, an RFID tag 16 may be located inor on a fin 15 f (as seen in FIGS. 4B and 4C). The RFID tag 16 wouldthereby be located close to the inner surface of the tubular string 5 s,potentially closer to the antenna 38 than when centralized. Closerproximity of the RFID tag 16 to the antenna 38 may provide bettertransmission of command signals. When located on a fin 15 f, it may bedesirable to affix the RFID tag 16 to the “back” of the fin 15 f—thesurface nearest the mandrel—so that the fin 15 f shelters the RFID tag16 during downhole travel.

The non-compressed diameter of the fins 15 f may correspond to, such asbeing equal to, greater than, or substantially greater than, an innerdiameter of the tubular string 5 s. The finned seal may engage thetubular string 5 s as the dart 15 is pumped through the bore thereof forsealing engagement therewith, for centering the dart therein, and formaintaining orientation of the RFID tag 16 relative to the tubularstring 5 s. The orientation may be a parallel relationship between alongitudinal axis of the RFID tag 16 and a longitudinal axis of thetubular string 5 s. The longitudinal axis of the RFID tag 16 may vary by+/−45 degrees from parallel with the longitudinal axis of the tubularstring 5 s to provide for more reliable transmission of command signals.

The gate of the tag carrier launcher 14 may include a housing, aplunger, and a shaft. The gate housing may be connected to a respectivelug formed in an outer surface of the launcher body, such as by threadedcouplings. The plunger may be longitudinally movable relative to thehousing and radially movable relative to the body between a captureposition and a release position. The plunger may be moved between thepositions by a linkage, such as a jackscrew, with the shaft. The shaftmay be longitudinally connected to and rotatable relative to thehousing. The launcher actuator may be a hydraulic motor operable torotate the shaft relative to the housing. The actuator may include areservoir (not shown) for receiving the spent hydraulic fluid, or theswivel 13 may include a second inlet and outlet for returning the spenthydraulic fluid to the HPU.

In operation, when it is desired to launch the dart 15, the console 17may be operated to supply hydraulic fluid to the launcher actuator viathe swivel 13. The launcher actuator may then move the plunger to therelease position. The canister and dart 15 may then move downwardrelative to the launcher body until the landing shoulders engage.Engagement of the landing shoulders may close the canister bypasspassages, thereby forcing the drilling fluid 20 d to flow into thecanister bore. The drilling fluid 20 d may then propel the dart 15 fromthe canister bore into a bore of the launcher adapter and onward throughthe tubular string 5 s.

Optionally, the launcher adapter may include an electronics package andantenna for reading the RFID tag 16 as the dart 15 is pumpedtherethrough for confirmation of launching of the dart and transmissionof a confirmation signal to the control console 17. Alternatively, theswivel 13 and launcher actuator may be pneumatic or electric.Alternatively, the launcher actuator may be linear, such as a piston andcylinder. Alternatively, the tag carrier launcher 14 may include a mainbody having a main bore and a parallel side bore, with both bores beingmachined integral to the main body. The dart 15 may be loaded into themain bore, and a dart releaser valve may be provided below the dart tomaintain it in the capture position. The dart releaser valve may beside-mounted externally and extend through the main body. A port in thedart releaser valve may provide fluid communication between the mainbore and the side bore. In a bypass position, the dart 15 may bemaintained in the main bore with the dart releaser valve closed. Fluidmay flow through the side bore and into the main bore below the dart viathe fluid communication port in the dart releaser valve. To release thedart 15, the dart releaser valve may be turned, such as by ninetydegrees, thereby closing the side bore and opening the main bore throughthe dart releaser valve. The drilling fluid 20 d may then enter the mainbore behind the dart 15, causing it to drop downhole.

The top drive 4 may include a motor for rotating 11 r the drill string5. The top drive motor may be electric or hydraulic. A frame of the topdrive 4 may be coupled to a rail (not shown) of the derrick 3 d forpreventing rotation thereof during rotation 11 r of the drill string 5,and allowing for vertical movement of the top drive with a travelingblock 12 t of the rig hoist 12. The frame of the top drive 4 may besuspended from the derrick 3 d by the traveling block 12 t. Thetraveling block 12 t may be supported by wire rope 12 w connected at itsupper end to a crown block 12 c of the rig hoist 12. The wire rope 12 wmay be woven through sheaves of the blocks 12 c,t and extend to drawworks 12 d of the hoist 12 for reeling thereof, thereby raising orlowering the traveling block 12 t relative to the derrick 3 d.

The PCA 1 p may include one or more blow out preventers (BOPs) and aflow cross. A housing of each BOP and the flow cross may each beinterconnected and/or connected to a wellhead 22, such as by a flangedconnection. The wellhead 22 may be mounted on a tubular string, such asouter casing string 23 which has been deployed into a wellbore 24drilled from a surface 25 of the earth and cemented into the wellbore. Atubular string, such as inner casing string 26 has been deployed intothe wellbore 24, hung from the wellhead 22, and cemented into place. Theinner casing string 26 may extend to a depth adjacent a bottom of anupper formation 27 u. The upper formation 27 u may be non-productive anda lower formation 27 b may be a hydrocarbon-bearing reservoir.

Alternatively, the lower formation 27 b may be non-productive (e.g., adepleted zone), environmentally sensitive, such as an aquifer, orunstable. Alternatively, the wellbore 24 may be subsea having a wellheadlocated adjacent to the waterline and the drilling rig 1 r may be alocated on a platform adjacent the wellhead. Alternatively, the wellbore24 may be subsea having a wellhead located adjacent to the seafloor andthe drilling rig 1 r may be a located on an offshore drilling unit.

The fluid system 1 f may include a pressure gauge 21, a mud pump 28, adrilling fluid reservoir, such as a pit 29 or tank, a solids separator,such as a shale shaker 30, a return line 31, a feed line, and a supplyline 32. A first end of the return line 31 may be connected to a branchof the flow cross and a second end of the return line may be connectedto an inlet of the shaker 30. A lower end of the supply line 32 may beconnected to an outlet of the mud pump 28 and an upper end of the supplyline may be connected to an inlet of the top drive 4. The pressure gauge21 may be assembled as part of the supply line 32. A lower end of thefeed line may be connected to an outlet of the pit 29 and an upper endof the feed line may be connected to an inlet of the mud pump 28. Thepressure gauge 21 may be used to monitor standpipe pressure.

The drilling fluid 20 d may include a base liquid. The base liquid maybe refined and/or synthetic oil, water, brine, or a water/oil emulsion.The drilling fluid 20 d may further include solids dissolved orsuspended in the base liquid, such as organophilic clay, lignite, and/orasphalt, thereby forming a mud.

To extend the wellbore 24 from a shoe of the inner casing string 26 intothe lower formation 27 b, the mud pump 28 may pump the drilling fluid 20d from the pit 29, through a standpipe and mud hose of the supply line32 to the top drive 4. The drilling fluid 20 d may flow from the supplyline 32 and into the drill string 5 via the top drive 4. The drillingfluid 20 d may be pumped down through the drill string 5 and exit thedrill bit 10, where the fluid may circulate the cuttings away from thebit and return the cuttings up an annulus 33 formed between an innersurface of the inner casing 26 or wellbore 24 and an outer surface ofthe drill string 5. The returns 20 r (drilling fluid plus cuttings) mayflow up the annulus 33 to the wellhead 22 and exit the wellhead at theflow cross. The returns 20 r may continue through the return line 31 andinto the shale shaker 30 and be processed thereby to remove thecuttings, thereby completing a cycle. As the drilling fluid 20 d andreturns 20 r circulate, the drill string 5 may be rotated 11 r by thetop drive 4 and lowered 11 a by the traveling block 12 t, therebyextending the wellbore 24 into the lower formation 27 b.

FIGS. 3A-3C illustrate an example control sub 6 and an example downholetool, namely circulation sub 7. The control sub 6 may include the stop19, a housing 34, an electronics package 35, an electrical power source,such as a battery 36, a piston 37, an antenna 38, a mandrel 39, and anactuator 40. The bore 39 b of the control sub 6 may be within themandrel 39. The housing 34 may include two or more tubular sections 34a-e connected to each other, such as by threaded couplings. The housing34 may have couplings, such as threaded couplings, formed at eachlongitudinal end thereof for connection to the tubular string 5 s at anupper end thereof and the circulation sub 7 at a lower end thereof. Thehousing 34 may have a pocket formed between a fourth section 34 d andthe lower section 34 e for receiving the antenna 38 and the mandrel 39.As may be recognized by those skilled in the pertinent art based on theteachings herein, the tag delivery system of the present disclosure mayemploy a variety of control subs and downhole tools, which may take anyof numerous different shapes or configurations.

The stop 19 may include a retainer 19 r and a seat 19 s. The retainer 19r may include a metal or alloy and the seat 19 s may include a flexiblematerial, such as rubber or an elastomer or elastomeric copolymer. Theretainer 19 r may be connected to the housing 34 by entrapment of anupper portion thereof between a bottom of the upper housing section 34 aand a shoulder formed in an inner surface of the second housing section34 b. The seat 19 s may be fitted or molded to a lower portion of theretainer 19 r. The seat 19 s may have cylindrical upper and lowerportions and a conical mid portion extending between the upper and lowerportions. The upper portion of the seat 19 s may have a larger innerdiameter than the lower portion thereof and the conical portion mayconverge from the upper portion to the lower portion to accommodate thedifference in diameters between the upper and lower portions.

The inner diameter of the seat upper portion may be greater than theouter diameter of the ball stud 15 b, and the inner diameter of the seatlower portion may be less than the outer diameter of the ball stud 15 b,such that the ball stud 15 b may be caught in the seat conical portion(FIG. 5B) as the dart 15 is pumped through the control sub 6. As usedherein, to be caught includes both slowing as well as coming to acomplete halt. In other words, when the catch element of a tag carrieris caught by a stop 19, progress of the tag carrier downhole through thebore of the control sub 6 is slowed sufficiently for reliabletransmission of a command signal from the RFID tag 16 on the tag carrierto the control sub 6 of the stop. A length of the dart 15 may correspondto a distance between the seat 19 s and the antenna 38 such that theRFID tag 16 is aligned with the antenna 38 when the dart is caught inthe seat. A seat chamber 19 c may be formed in an inner surface of thesecond housing section 34 b to accommodate expansion of the seat 19 sduring passage of the dart 15 therethrough. A stiffness of the seat 19 smay be sufficient to absorb kinetic energy of the dart 15 as the dart isbeing pumped through the tubular string 5 s, thereby slowing or haltingadvancement of the dart (and the RFID tag 16). In some embodiments, theseat 19 s may be configured so that the outer surface of the seat 19 sdoes not significantly deform when the ball stud 15 b is caught. Forexample, the stiffness of the seat 19 s may increase radially, such thatwhen the ball stud 15 b is caught, the inner surface of the seat 19 scompresses to absorb the impact, while the outer surface of seat 19 sremains relatively fixed. In such embodiments, the seat chamber 19 c maybe only narrowly larger than the outer surface of seat 19 s. In someembodiments, two or more seats 19 s may be used in a stop 19. In someembodiments, two or more stops 19 may be used in a control sub 6.

Advantageously, slowing or halting of the RFID tag 16 may allow for thecontrol sub 6 to have a shorter antenna 38 than would otherwise beneeded if the tag were traveling through the control sub 6 at asignificant speed. The antenna 38 may have a length less than or equalto about five feet (about one hundred fifty-two centimeters), such asless than or equal to about three feet (about ninety-one centimeters) orless than or equal to about two feet (about sixty-one centimeters). Theantenna length may also be greater than or equal to a length of the RFIDtag 16. Further, having the orientation of the RFID tag 16 and thecentralized position fixed by the dart 15 also allows confidence inusing only one RFID tag to transmit a command signal to the control sub6, instead of otherwise having to launch several tags and relying onprobability to ensure that one of the tags will be in the properorientation and centralized position. The longitudinal axis of the RFIDtag 16 may vary by +/−45 degrees from parallel with the longitudinalaxis of the tubular string 5 s to provide for more reliable transmissionof command signals.

Alternatively, the seat 19 s may include a malleable, ductile, and/orresilient metal or alloy, such as brass. The alternative metallic seatmay be seamless or have a longitudinal seam weld (not shown). Thealternative metallic seat may have a thin wall thickness such that theseat is pliable to longitudinally, radially, and/or circumferentiallyexpand for passage of the dart 15 therethrough. The thin seat wallthickness may be equal to a thickness of sheet metal (six thousandths ofan inch to twenty-four hundredths of an inch or two to six tenths of amillimeter) or foil (one to five thousandths of an inch or three tothirteen hundredths of a millimeter). Alternatively, the seat 19 s mayinclude a plurality of segments to mechanically actuate from theexpanded position to the contracted position.

The antenna 38 may include an inner sleeve 38 r, a coil 38 c, an outersleeve 38 s, a nut 38 n, an upper sleeve 38 u, and a plug 38 p. Theinner sleeve 38 r may include a non-magnetic and non-conductivematerial, such as a polymer or composite, may have a bore formedlongitudinally therethrough, and may have a helical groove formed in anouter surface thereof. The coil 38 c may be wound in the helical grooveand made from an electrically conductive material, such as copper or analloy thereof. The outer sleeve 38 s may include the non-magnetic andnon-conductive material and may insulate the coil 38 c. A seal may bedisposed in an upper interface of the inner sleeve 38 r and the outersleeve 38 s. The nut 38 n, upper sleeve 38 u, and the plug 38 p may eachinclude the non-magnetic and non-conductive material. The plug 38 p mayreceive ends of the coil 38 c.

The upper sleeve 38 u of the antenna may be connected to the innersleeve 38 r, such as by a threaded connection, and be received in areceptacle formed in an inner surface of the third housing section 34 c.The nut 38 n may be connected to the outer sleeve 38 s, such as by athreaded connection, and the antenna plug 38 p may be connected to theinner sleeve 38 r, such as one or more threaded fasteners (not shown). Aseal may be disposed in an interface of the inner sleeve 38 r and theplug 38 p. The plug 38 p may have an electrical conduit formedtherethrough for receiving the coil ends and a recess for housing anelectric plug and receiving an electric socket 41 disposed in an upperend of the mandrel 39. A seal may be disposed in an interface of themandrel 39 and the plug 38 p. A balance piston 42 may be disposed in areservoir chamber formed between the fourth housing section 34 d and theouter antenna sleeve 38 s and may divide the chamber into an upperportion and a lower portion. One or more ports of the upper sleeve 38 umay provide fluid communication between the reservoir chamber upperportion and a bore of the control sub 6. Hydraulic fluid, such asrefined and/or synthetic oil 43, may be disposed in the reservoirchamber lower portion. The balance piston 42 may carry inner and outerseals for isolating the hydraulic oil 43 from the bore of the controlsub 6. Each of the nut 38 n and the plug 38 p may have a hydraulicpassage formed therethrough.

The mandrel 39 may be a tubular member having one or more recessesformed in an outer surface thereof. The mandrel 39 may be connected tothe fourth housing section 34 d, such as by one or more threadedfasteners (not shown). The mandrel 39 may have electrical conduitsformed in a wall thereof for receiving lead wires connecting the socket41 to the electronics package 35, and for connecting the battery 36 tothe electronics package 35. The mandrel 39 may also have a hydraulicpassage formed therethrough for providing fluid communication betweenthe reservoir and the actuator 40. One or more seals may be disposed inan interface between the fourth housing section 34 d and the mandrel 39.The mandrel 39 may have another electrical conduit formed in the wallthereof for receiving lead wires connecting the electronics package 35to the actuator 40.

The electronics package 35 and battery 36 may be disposed in respectiverecesses of the mandrel 39. The electronics package 35 may include acontrol circuit 35 c, a transmitter 35 t, a receiver 35 r, and a motorcontroller 35 m integrated on a printed circuit board 35 b. The controlcircuit 35 c may include a microcontroller (MCU), a memory unit (MEM), aclock, and an analog-digital converter. The transmitter 35 t may includean amplifier (AMP), a modulator (MOD), and an oscillator (OSC). Thereceiver 35 r may include an amplifier (AMP), a demodulator (MOD), and afilter (FIL). The motor controller 35 m may include an inverter forconverting DC power supplied by the battery 36 into suitable power fordriving an electric motor 40 m of the actuator 40.

The actuator 40 may include the electric motor 40 m, a gearbox 40 g, apump 40 p, one or more control valves 44 u,b, and one or more pressuresensors (not shown). The electric motor 40 m may include a stator inelectrical communication with the motor controller 35 m and a rotor inelectromagnetic communication with the stator for being torsionallydriven thereby. The gearbox 40 g may have an input shaft torsionallyconnected to the rotor. The pump 40 p may have a stator connected to themotor stator and a head connected to an output shaft of the gearbox 40 gfor being driven thereby. The pump head may be longitudinally ortorsionally driven. The pump 40 p may have an inlet in fluidcommunication with the mandrel hydraulic passage and an outlet in fluidcommunication with a first control valve 44 u. The second control valve44 b may also be in fluid communication with the mandrel hydraulicpassage.

The circulation sub 7 may include a housing 45, a liner sleeve 46, avalve sleeve 47, and one or more (pair shown) circulation ports 48. Thehousing 45 may be tubular and may have couplings, such as threadedcouplings, formed at each longitudinal end thereof for connection to thecontrol sub 6 at an upper end thereof and the catcher 8 at a lower endthereof.

The piston 37 may be disposed in the lower housing section 34 e and thehousing 45, and may be longitudinally movable relative thereto betweenan upper position (FIG. 6A) and a lower position (FIG. 3C). The piston37 may be stopped in the lower position against a shoulder formed in aninner surface of the housing 45. The circulation ports 48 may be formedthrough a wall of the housing 45. The liner sleeve 46 may be disposedbetween the piston 37 and the housing 45. The liner sleeve 46 may haveone or more ports formed therethrough in alignment with the circulationports 48. The liner sleeve 46 may include an erosion resistant material,such as a metal, alloy, ceramic, or cermet. A seal may be disposed in aninterface between the liner sleeve 46 and the housing 45.

The valve sleeve 47 may be connected to a lower end of the piston 37,such as by threaded couplings. A seal may be disposed in the interfacebetween the valve sleeve 47 and the piston 37. The valve sleeve 47 mayhave one or more ports formed therethrough and corresponding to thecirculation ports 48. The valve sleeve 47 may also carry a seal adjacentto the ports thereof and in engagement with an inner surface of theliner sleeve 46. The valve sleeve/piston interface may cover the linerports when the piston 37 is in the lower position, thereby closing thecirculation ports 48, and the valve sleeve ports may be aligned with thecirculation ports when the piston is in the upper position, therebyopening the circulation ports.

The control sub 6 may further include a detent 49 disposed between thehousing 34 and the piston 37 and connected to a lower end of the lowerhousing section 34 e, such as by threaded couplings. A seal may bedisposed in an inner surface of the detent 49 in engagement with anouter surface of the piston 37. A seal may be disposed in an interfacebetween the lower housing section 34 e and the detent 49 and may serveas a lower end of an actuation chamber. A shoulder formed in an outersurface of the piston 37 may be disposed in the actuation chamber andcarry a seal in engagement with an inner surface of the lower housingsection 34 e. The piston shoulder may divide the actuation chamber intoan opener portion and a closer portion. A shoulder formed in an innersurface of the lower housing section 34 e may have a seal in engagementwith an outer surface of the piston 37 and may serve as an upper end ofthe actuation chamber. Collet fingers may be formed in an upper end ofthe detent 49. The piston 37 may have a detent profile formed in anouter surface thereof complementary to the collet fingers. Engagement ofthe fingers with the detent profile may stop the piston 37 in the upperposition.

Each end of the actuation chamber may be in fluid communication with arespective control valve 44 u,b via a respective hydraulic passageformed in a wall of the lower housing section 34 e. Each control valve44 u,b may also be in fluid communication with an opposite hydraulicpassage via a crossover passage. The control valves 44 u,b may each beelectronically actuated, such as by a solenoid, and together may provideselective fluid communication between an outlet of the pump and theopener and closer portions of the actuation chamber while providingfluid communication between the reservoir chamber and an alternate oneof the opener and closer portions of the actuation chamber. Each controlvalve actuator may be in electrical communication with the MCU of thecontrol circuit 35 c for control thereby. A pressure sensor may be influid communication with the reservoir chamber and another pressuresensor may be in fluid communication with an outlet of the pump 40 p andeach pressure sensor may be in electrical communication with the MCU toindicate when the piston 37 has reached the respective upper and lowerpositions by detecting a corresponding pressure increase at the outletof the pump.

FIGS. 4A, 4B, 4C, and 4D illustrate the dart 15 and the RFID tag 16. TheRFID tag 16 may be a passive tag and include an electronics package andone or more antennas disposed in a non-metallic cylinder having endsclosed by caps. The electronics package may include a memory unit, atransmitter, and a radio frequency power generator for operating thetransmitter. The RFID tag 16 may be programmed with a command for thecirculation sub 6, such as to shift to the next position. The RFID tag16 may be operable to transmit the command signal 50 c (FIG. 5B), suchas a digital electromagnetic command signal (that may includeidentification information), to the antenna 38 in response to receivingan activation signal 50 a (FIG. 5B) therefrom. The MCU of the controlcircuit 35 c may receive the command signal 50 c and operate theactuator 40 in response to receiving the command signal.

FIG. 4F illustrates an alternative wireless identification and sensingplatform (WISP) tag 51 w for use with the tag delivery system 2,according to another embodiment of the present disclosure.Alternatively, the RFID tag 16 may be a WISP tag 51 w. The WISP tag 51 wmay further include a microcontroller (MCU) and a receiver for beingprogrammable at the surface 25. Suitable WISP tags may be selected froma family of sensors that are powered and/or read by ultra-high frequencyRFID readers. WISP tags may not require batteries, being capable ofharvesting power from the radio frequency signal generated by thereader. For example, a suitable WISP tag may be an open source, openarchitecture EPC Class 1 Generation 2 RFID tag that includes a fullyprogrammable 16 bit microcontroller, as well as arbitrary sensors.

FIG. 4E illustrates an alternative active tag 51 a for use with the tagdelivery system 2, according to another embodiment of the presentdisclosure. Alternatively, the RFID tag 16 may be an active tag 51 ahaving an onboard battery powering a transmitter instead of having theradio frequency power generator, or the WISP tag 51 w may have anonboard battery for assisting in data handling functions.

FIGS. 5A-5D illustrate an example operation of the tag delivery system2. Referring specifically to FIG. 5A, periodically, during or afterdrilling of the wellbore 24, it may be desirable to perform a downholeoperation, such as a cleanout operation to clear the annulus 33 ofcuttings. The cleanout operation may involve rotation 11 r of the drillstring 5 at a high angular velocity and circulation through the annulus33 at a flow rate greater than what is capable through the drill bit 10.In preparation of the cleanout operation, a technician may operate thetag carrier launcher 14 via the control console 17. This may provide anadditional safety mechanism in embodiments wherein the control console17 is located remotely from the drilling rig 1 r. The dart 15 may bereleased and propelled into the tubular string 5 s by drilling fluid 20d pumped by the mud pump 28.

Referring specifically to FIG. 5B, the tag carrier may travel down thetubular string 5 s and into the control sub 6 until the catch element iscaught by the seat 19 s. For example, the dart 15 may travel down thetubular string 5 s and into the control sub 6 until the ball stud 15 bis caught by the seat 19 s. The RFID tag thereby may be aligned with theantenna when the tag carrier is caught by the seat. The RFID tag 16 mayreceive the activation signal 50 a from the antenna 38 and reply bytransmitting the command signal 50 c thereto. In the illustratedembodiment, the MCU of the control circuit 35 c may operate the actuator40 to shift the valve sleeve 47 upward to the open position,facilitating the cleanout operation. Continued pumping of the drillingfluid 20 d against the stopped dart 15 may increase pressure 52 in thebore of the tubular string 5 s. The increase in pressure 52 may bedetected at the surface 25 by monitoring the pressure gauge 21.

Referring specifically to FIG. 5C, the pressure 52 exerted on the ballstud 15 b may increase until a threshold pressure is achieved, therebypassing the dart 15 through the seat 19 s by expansion of the seat, toallow passage of the dart therethrough. Referring specifically to FIG.5D, once the ball stud 15 b has passed through the seat 19 s, thepressure 52 may decrease, and the dart 15 may resume downward travelthrough the control sub 6 and the circulation sub 7. The outer diameterof the ball stud 15 b may be less than a diameter of the antenna innersleeve 38 r to prevent damage to the antenna 38 as the ball stud 15 bpasses therethrough.

FIG. 6A illustrates a cleanout operation being performed using thecirculation sub 7. The catcher 8 may include a tubular housing, atubular cage, and a baffle. The catcher housing may have threadedcouplings formed at each longitudinal end thereof for connection withthe circulation sub 7 at an upper end thereof and the drill collars 9 ata lower end thereof. The catcher housing may have a longitudinal boreformed therethrough for passage of the drilling fluid 20 d therethrough.An inner surface of the catcher housing may have an upper and lowershoulder formed therein.

The catcher cage may be disposed within the catcher housing andconnected thereto, such as by being disposed between the lower housingshoulder and a fastener, such as a ring, connected to the housing, suchas by a threaded connection. The catcher cage may include an erosionresistant material, such as a tool steel or cermet, or include a metalor alloy and treated, such as a case hardened, to resist erosion. Theretainer ring may engage the upper housing shoulder. The catcher cagemay have solid top and bottom and a perforated body, such as slotted.The slots may be formed through a wall of the body and spacedtherearound. A length of the catcher cage may correspond to a capacityof the catcher 8 and may be sized to catch a plurality of darts 15 sothat the circulation sub 7 may be repeatedly actuated between thepositons. The baffle may be fastened to the body, such as by one or morefasteners (not shown). An annular flow passage may be formed between thebody and the housing. The annular flow passage may serve as a bypass forthe flow of the drilling fluid 20 d through the catcher 8.

The dart 15 may continue downward travel through the BHA 5 b until thedart lands on the baffle. The drilling fluid 20 d may enter the annularflow passage from the housing bore through the slots, flow around thecaught dart 15 and along the annulus, and re-enter the housing borethorough the slots below the baffle. The cleanout operation may commenceonce the circulation sub 7 has opened. Once the cleanout operation hasconcluded, a second dart (not shown) carrying a second RFID tag may belaunched and pumped down the tubular string 5 s to command the controlsub 6 to close the circulation ports 48 for the resumption of drilling.

FIG. 6B illustrates an arrival sensor 54 for the tag delivery system,according to another embodiment of the present disclosure. Analternative stop 53 may include a modified retainer 53 r, the seat 19 s,and the arrival sensor 54. The modified retainer 53 r may include ametal or alloy. The modified retainer 53 r may be linked to a modifiedhousing 55 by entrapment of an upper portion thereof between a bottom ofthe upper housing section 34 a and a shoulder formed in an inner surfaceof a modified second housing section 55 b. The seat 19 s may be fittedor molded to a lower portion of the modified retainer 53 r. The arrivalsensor 54 may include a pair of switch rings 54 a,b, a bridge ring 54 c,and a spring 54 s, such as a compression spring.

A distance between the bottom of the upper housing section 34 a and theshoulder of the modified second housing section 55 b may be greater thana length of an enlarged upper portion of the modified retainer 53 r,thereby providing room to accommodate longitudinal movement of themodified retainer between an upper position (shown) and a lower position(not shown). A chamber may be formed between the shoulder of themodified second housing section 55 b and a shoulder of the modifiedretainer 53 r. The spring 54 s may be disposed in the chamber and havean upper end pressing against the shoulder of the modified retainer 53 rand a lower end pressing against the shoulder of the modified secondhousing section 55 b, thereby biasing the modified retainer toward theupper position.

The switch rings 54 a,b may be disposed in respective grooves formed inthe inner surface of the modified second housing section 55 b adjacentto the chamber. The switch rings 54 a,b may be spaced apart by adistance preventing electrical communication therebetween. The modifiedhousing 55 may have electrical conduits formed in a wall thereof forreceiving lead wires connecting the switch rings 54 a,b to theelectronics package 35 and contact rings for providing electricalcommunication across joints between the housing sections. The bridgering 54 c may be disposed in a groove formed in an outer surface of theenlarged portion of the modified retainer 53 r. The bridge ring 54 c mayhave a length corresponding to the distance between the switch rings 54a,b. The bridge ring 54 c may be clear of the switch rings 54 a,b whenthe modified retainer is in the upper position and aligned with theswitch rings when the modified retainer is in the lower position.

In operation, the MCU of the control circuit 35 c may supply a voltageto the switch rings 54 a,b and monitor the circuit thereof for currentflow. The force exerted on the landed dart 15 by the increased pressure52 may drive the modified retainer 53 r from the upper position to thelower positon, thereby aligning the bridge ring 54 c with the switchrings 54 a,b, closing the circuit therebetween, and allowing current toflow. The MCU may detect the current flow and activate the antenna 38 inresponse to the detected current flow, thereby conserving life of thebattery 36. Once the dart 15 has passed through the seat 19 s, thespring 54 s may return the modified retainer 53 r to the upper position,thereby opening the circuit between the switch rings 54 a,b. The MCU mayshut off electrical power to the antenna 38 in response to detectingloss of current flow.

Alternatively, the switch rings 54 a,b may be electrically connected inseries between the antenna 38 and the electronics package 35.Alternatively, the arrival sensor 54 may be a pressure sensor in fluidcommunication with a bore of the upper housing section 34 a or theretainer 19 r.

FIG. 6C illustrates an alternative arrival sensor 91 for the tagdelivery system, according to another embodiment of the presentdisclosure. An alternative stop 92 may include the retainer 19 r, amodified seat 92 s, and a pair of switch ring segments 94 a,b embeddedin an inner surface of the modified seat. Lead wires may extend from themodified seat 92 s into a modified housing 93 having electrical conduitsformed in a wall thereof. The lead wires may connect the switch ringsegments 94 a,b to the electronics package 35, and the modified housing93 may have contact rings for providing electrical communication acrossjoints between the housing sections. A modified dart 95 may carry thebridge ring 54 c in an outer surface of the ball stud 15 b.

In operation, the MCU of the control circuit 35 c may supply a voltageto the switch ring segments 94 a,b and monitor the circuit thereof forcurrent flow. Landing of the modified dart 95 into the modified seat 92s may align the bridge ring 54 c with the switch ring segments 94 a,b,thereby closing the circuit therebetween and allowing current to flow.The MCU may detect the current flow and activate the antenna 38 inresponse to the detected current flow, thereby conserving life of thebattery 36. Passing of the modified dart 95 through the modified seat 92s may open the circuit between the switch ring segments 94 a,b. The MCUmay shut off electrical power to the antenna 38 in response to detectingloss of current flow.

Alternatively, the switch ring segments 94 a,b may be electricallyconnected in series between the antenna 38 and the electronics package35.

FIG. 7A illustrates an alternative downhole tool, such as alternativecirculation sub 57, according to another embodiment of the presentdisclosure. The alternative circulation sub 57 may include a housing 56,the liner sleeve 46, a valve sleeve 58, the circulation ports 48, and abore valve 60. The housing 56 may be tubular and may have couplings,such as threaded couplings, formed at each longitudinal end thereof forconnection to the control sub 6 at an upper end thereof and a shoe 59(FIG. 7B) at a lower end thereof.

The valve sleeve 58 may be connected to a lower end of the piston 37,such as by threaded couplings. A seal may be disposed in the interfacebetween the valve sleeve 58 and the piston 37. The valve sleeve 58 mayhave one or more ports formed therethrough and corresponding to thecirculation ports 48. The valve sleeve 58 may also carry a seal adjacentto the ports thereof and in engagement with an inner surface of theliner sleeve 46. The valve sleeve/piston interface may cover the linerports when the piston 37 is in the lower position, thereby closing thecirculation ports 48, and the valve sleeve ports may be aligned with thecirculation ports when the piston is in the upper position, therebyopening the circulation ports.

The piston 37 may be stopped in the lower position by the bore valve 60.The bore valve 60 may be operable between an open position (FIG. 8B) anda closed position (FIG. 7A) by interaction with the valve sleeve 58. Inthe open position, the bore valve 60 may allow flow through thealternative circulation sub 57 to the shoe 59. In the closed position,the bore valve 60 may close the circulation sub bore below thecirculation ports 48, thereby preventing flow to the shoe 59 anddiverting all flow through the circulation ports. The bore valve 60 maybe operably coupled to the valve sleeve 58 such that the bore valve isopen when the circulation ports 48 are closed and the bore valve isclosed when the circulation ports are open.

The bore valve 60 may include a cam 61, upper 62 u and lower 62 b seats,and a valve member, such as a ball 63. The cam 61 may be connected tothe housing 56 by being trapped within a recess formed therein. Eachseat 62 u,b may be disposed between the valve sleeve 58 and the ball 63and biased into engagement with the ball by a respective spring disposedbetween the respective seat and the valve sleeve. The ball 63 may belongitudinally connected to the valve sleeve 58 by being trapped inopenings formed through a wall thereof. The ball 63 may be disposedwithin the cam 61 and may be rotatable relative thereto between an openposition and a closed position by interaction with the cam. The ball 63may have a bore therethrough corresponding to the piston/sleeve bore andaligned therewith in the open position. A wall of the ball 63 mayisolate the shoe 59 from the alternative circulation sub 57 in theclosed position. The cam 61 may interact with the ball 63 by having acam profile, such as slots, formed in an inner surface thereof. The ball63 may carry corresponding followers 64 in an outer surface thereof andengaged with respective cam profiles or vice versa. The ball-caminteraction may rotate the ball 63 between the open and closed positionsin response to longitudinal movement of the ball relative to the cam 61.

FIGS. 7B-9B illustrate an inner string cementing operation performedusing the control sub 6 and the alternative circulation sub 57.Referring specifically to FIG. 7B, the control sub 6 and the alternativecirculation sub 57 may be part of a tubular string, such as work string65 of an offshore drilling system (rest not shown). The work string 65may further include the tubular string 5 s, the shoe 59, and a runningtool 71. The offshore drilling system may further include an offshoredrilling unit, a drilling rig, a fluid handling system, and the tagdelivery system 2. The drilling rig may be similar to the (terrestrial)drilling rig 1 r except for the addition of a cementing swivel connectedbetween the (hydraulic) swivel 13 and the tag carrier launcher 14. Thefluid handling system may be similar to the (terrestrial) fluid handlingsystem 1 r except for the addition of a cement blender and a cement pumphaving an outlet connected to a cementing swivel and an inlet connectedto the blender.

The offshore drilling unit may be positioned over a wellhead 66 locatedadjacent to a floor 67 f of the sea 67. A tubular string 68 has beendriven into the seafloor 67 f. The tubular string 68 may include anouter wellhead housing 68 h and joints of conductor pipe 68 p connectedtogether, such as by threaded couplings. Once the tubular string 68 hasbeen set, a subsea wellbore 69 may be drilled into the seafloor 67 f,and the work string 65 may be used to deploy a surface tubular string,such as casing string 70 into the wellbore 69. During deployment of thesurface casing string 70, the alternative circulation sub 57 may be in adeployment position having the circulation ports 48 open and the borevalve 60 closed. The surface casing string 70 may include an innerwellhead housing 70 h, joints of casing 70 c connected together, such asby threaded couplings, a float collar 70 f, and a shoe 70 s.

The float collar 70 f may include a tubular housing, a shutoff valve, areceptacle, and a bonding material. Inner components of the float collar70 f and shoe 70 s may include a drillable material, such as cement,non-ferrous metal or alloy, polymer, or fiber reinforced composite. Theshutoff valve may include a pair of oppositely oriented check valves,such as an upward opening flapper valve and a downward opening flappervalve, arranged in series. Each flapper valve may include a body and aflapper pivotally connected to the body and biased toward a closedposition, such as by a torsion spring (not shown). The flapper valvesmay be separated by a spacer and the opposed arrangement of theunidirectional flapper valves may provide bidirectional capability tothe shutoff valve. The flapper valves may be propped open by the shoe 59and/or housing 56 and the receptacle may have a shoulder carrying a sealfor engaging an outer surface of the shoe 59 or housing 56, therebyisolating an interface between the work string 65 and the surface casingstring 70. Once the work string 65 is removed from the surface casingstring 70 (FIG. 9B), the flappers may close to isolate a bore of thesurface casing string from the wellbore 69.

The inner wellhead housing 70 h may land in the outer wellhead housing69 h during deployment of the surface casing string 70 into the wellbore69, thereby forming the subsea wellhead 66. Once the surface casingstring 70 has landed, a technician may operate the tag carrier launcher14 via the control console 17. The cement pump may then be operated andthe dart 15 may be released and propelled into the tubular string 5 s bycement slurry 72 pumped through the cementing swivel.

Once the desired quantity of cement slurry 72 has been pumped, chaserfluid (not shown) may be pumped into the cementing swivel by the cementpump. Pumping of the chaser fluid may be switched to the mud pump oncethe cement line has been purged. The dart 15 and cement slurry 72 maypass through the work string 65 by the chaser fluid. Seawater 73displaced from the work string 65 may exit the circulation ports 48 andflow up an inner annulus 74 formed between the work string 65 and thesurface casing string 70 and be discharged into the sea 67. The closedbore valve 60 may prevent the displaced seawater 73 from flowing throughthe shoes 59, 70 s and up an outer annulus 75 formed between the surfacecasing string 70 and the wellbore 69 which could otherwise washout theouter annulus. Washout of the outer annulus 75 may lower the finalcement level in the outer annulus by increasing the volume thereof,thereby compromising the integrity of the cement sheath.

Referring specifically to FIG. 8A, the dart 15 may travel down thetubular string 5 s and into the control sub 6 until the ball stud 15 bis caught by the seat 19 s. The RFID tag thereby may be aligned with theantenna when the ball stud 15 b of the dart is caught by the seat. TheRFID tag 16 may receive the activation signal 50 a from the antenna 38and reply by transmitting the command signal 50 c thereto. Referringspecifically to FIG. 8B, the MCU of the control circuit 35 c may operatethe actuator 40 to shift the valve sleeve 58 downward to close thecirculation ports 48 and open the bore valve 60. Continued pumpingagainst the stopped dart 15 may increase the pressure 52 in the bore ofthe tubular string 5 s exerted on the ball stud 15 b until the thresholdpressure is achieved, thereby passing the dart through the seat 19 s toallow passage of the dart therethrough.

Referring specifically to FIG. 9A, once the ball stud 15 b has passedthrough the seat 19 s, the pressure 52 may decrease and the dart 15 mayresume downward travel through the control sub 6 and the alternativecirculation sub 57 until reaching a bottom of the wellbore 69. Thecement slurry 72 may follow the dart 15 through the open bore valve 60and the shoes 59, 70 s and up the outer annulus 75. Pumping of thechaser fluid may continue until a top of the cement slurry 72 reaches adesired level in the outer annulus 75 adjacent to the tubular string 68.

Referring specifically to FIG. 9B, pumping of the chaser fluid may thenbe halted and the running tool 71 may be released from the innerwellhead housing 70 h. The work string 65 may be retrieved to the rig,thereby removing the alternative circulation sub 57 and/or shoe 59 fromobstructing closure of the float collar 70 f. The float collar 70 f maythen close to prevent backflow of the cement slurry 72 into a bore ofthe surface casing string 70.

Alternatively, the rig may include a second tag carrier launcher forlaunching a second dart into the tubular string 5 s after the cementslurry 72 has been pumped and before the chaser fluid is pumped. Thesecond dart may separate the cement slurry 72 from the chaser fluid. Thesecond dart may be similar to the (first) dart 15 except for omission ofthe RFID tag 16. Landing of the second dart in the seat may be detectedat the rig and used as an indication that the time to stop pumping ofthe chaser fluid is imminent.

FIG. 9C illustrates a cementing operation being performed using a firstalternative tag delivery system. The first alternative tag deliverysystem may be similar to the tag delivery system 2 except for includinga lead dart 96 d, a trail dart 96 t, and a second tag carrier launcher(not shown). Each dart 96 d,t may be similar to the dart 15. The secondtag carrier launcher may be similar to the tag carrier launcher 14except for omission of the deflector. The second tag carrier launchermay be connected between the tag carrier launcher 14 and the tubularstring 5 s and the swivel 13 may have a second inlet and outlet foroperation of the second tag carrier launcher. The darts 96 d,t may beemployed in a cementing operation for subsea tubular strings, such as asubsea casing string or a liner string. The lead dart 96 d may belaunched into the tubular string 5 s after the annulus has been cleanedby conditioner 97 c. A quantity of cement slurry 72 may then be pumpedinto the tubular string 5 s. The trail dart may be launched into thetubular string 5 s behind the cement slurry 72 and the train 72, 96 d,tmay pass through the tubular string 5 s by pumping chaser fluid 97 hinto the tubular string behind the trail dart 96 t.

FIGS. 10A-10C illustrate a first alternative control sub 76, accordingto another embodiment of the present disclosure. The first alternativecontrol sub 76 may include the stop 19, a housing 77, the electronicspackage 35, the battery 36, the antenna 38 (shown schematically), apiston 78, a mandrel 79, an actuator, such as control valve 80, and areturn spring 81. The housing 77 may include two or more tubularsections 34 a-c, 77 d, 77 e connected to each other, such as by threadedcouplings. The housing 77 may have couplings, such as threadedcouplings, formed at each longitudinal end thereof for connection to thetubular string 5 s at an upper end thereof and an underreamer (notshown) at a lower end thereof. The housing 77 may have a pocket formedbetween a fourth section 77 d and the lower section 77 e for receivingthe antenna 38 and the mandrel 79. The mandrel 79 may also include twoor more tubular sections 79 a-c connected to each other, such as bythreaded couplings.

A balance piston 82 may be disposed in a reservoir chamber formedbetween the upper mandrel section 79 a and the outer antenna sleeve, andmay divide the chamber into an upper portion and a lower portion. One ormore ports of the upper antenna sleeve may provide fluid communicationbetween the reservoir chamber upper portion and a bore of the firstalternative control sub 76. Hydraulic fluid, such as oil (not shown),may be disposed in the reservoir chamber lower portion. The balancepiston 82 may carry inner and outer seals for isolating the hydraulicoil from the bore of the first alternative control sub 76. Each of theantenna nut and the antenna plug may have a hydraulic passage formedtherethrough.

The mandrel 79 may have one or more recesses formed in an outer surfacethereof. The mandrel 79 may be connected to the fourth housing section77 d, such as by threaded couplings. The mandrel 79 may have electricalconduits formed in a wall thereof for receiving lead wires connecting anelectrical socket (not shown) to the electronics package 35, andconnecting the battery 36 to the electronics package 35. The mandrel 79may also have a hydraulic passage formed therethrough for providingfluid communication between the reservoir and the piston 78, and thecontrol valve 80 may be disposed in the passage for selectively openingand closing the passage. One or more seals may be disposed in aninterface between the fourth housing section 77 d and the mandrel 79.The mandrel 79 may have another electrical conduit formed in the wallthereof for receiving lead wires connecting the electronics package 35to the control valve 80.

The control valve 80 may be a solenoid operated shutoff or check valve.If the control valve 80 is a check valve, the solenoid may operate thevalve between a check position and an open position. In the checkposition, the valve may be oriented to prevent flow from the piston 78to the balance piston 82 and allow reverse flow therethrough. Theelectronics package 35 and battery 36 may be disposed in respectiverecesses of the mandrel 79. The motor controller 35 m may instead beused to supply appropriate power to the solenoid of the control valve 80for operation thereof between the positions.

The piston 78 may have an upper sleeve portion, a lower sleeve portion,and a shoulder portion connecting the sleeve portions. The lower sleeveportion of the piston 78 may extend into the underreamer when the firstalternative control sub 76 is connected thereto. A cap 84 may beconnected to a bottom of the lower sleeve portion, such as by threadedcouplings and/or fasteners. A control chamber may be formedlongitudinally between a bottom of the second mandrel section 79 b and ashoulder of the third mandrel section 79 c. The control chamber may beradially formed between an outer surface of the piston sleeve portionsand an inner surface of the third mandrel section 79 c. The shoulder ofthe piston 78 may be disposed in the control chamber and may divide thecontrol chamber into an upper portion and a lower portion.

The upper portion of the control chamber may be filled with hydraulicfluid and be in fluid communication with the reservoir chamber. Thelower portion of the control chamber may be in fluid communication withthe controller bore via ports formed through a wall of the piston lowersleeve portion. The return spring 81 may be a compression springdisposed in an upper portion of the control chamber between a lower faceof a guide sleeve 83 and an upper face of the shoulder of the piston 78,thereby biasing the cap 84 downward into engagement with a piston of theunderreamer.

The underreamer may include a body, the piston, one or more sealsleeves, a flow sleeve, and one or more arms. Each arm may be movablebetween an extended and a retracted position and may initially bedisposed in a pocket of the body in the retracted position. Each arm maybe pivotally connected to the piston, such as by a fastener. The bodymay have an extension profile formed in a pocket surface thereof foreach arm and a retraction profile formed in a pocket surface thereof foreach arm and each arm may have mating extension and retraction profilesformed therein. Upward movement of each arm may disengage the respectiveretraction profiles and engage the respective extension profiles,thereby forcing the arms radially outward from the retracted position tothe extended position. The underreamer may be fluid operated by drillingfluid injected through the tubular string being at a high pressure andreturns flowing up the annulus being at a lower pressure. The highpressure may act on a lower face of the underreamer piston and the lowpressure may act on an upper face of the piston, thereby creating a netupward actuation force and moving the arms from the retracted positionto the extended position.

The first alternative control sub 76 may selectively lock and unlock theunderreamer in the retracted position. In the locked position, eventhough force is exerted on the underreamer piston by the drilling fluid,the closed control valve 80 may prevent the underreamer piston fromextending the arms due to incompressibility of the hydraulic fluid inthe control chamber upper portion. The dart 15 may be pumped to the seat19 s when it is desired to unlock the underreamer. The MCU of thecontrol circuit may open the control valve 80 in response to receipt ofthe command signal, thereby allowing the underreamer piston to extendthe underreamer arms.

FIGS. 11 and 12A-12D illustrate a second alternative tag delivery system90 and operation thereof, according to another embodiment of the presentdisclosure. The second alternative tag delivery system 90 may includethe tag carrier launcher 14, a tag carrier, the RFID tag 16, the controlconsole 17, the HPU 18, and a seat 87. The tag carrier may be a pumpdown plug, such as a dart 85. The tag carrier launcher 14 may beassembled as part of alternative supply line 88 connecting the outlet ofthe mud pump 28 and the inlet of the top drive 4. In some operations itmay be desired to pump fluid (such as drilling fluid 20 d, cement slurry72, and/or chaser fluid 97 h) through the tubular string with minimalinterruption, referred to herein as continuous pumping. For example,this may be desired when performing cementing operations. A launcheractuator that can launch tag carriers without pumping interruption maybe advantageous to continuous pumping operations. As before, the controlconsole 17 may be located on or near the floor 3 f, at another locationon the drilling rig 1 r, or the control console 17 may be locatedremotely from the drilling rig 1 r.

As before, the tag carrier launcher 14 may include a body, a deflector,a canister, a gate, an adapter, and the actuator. The dart 85 may bedisposed in the canister bore. The dart 85 may include a finned portion85 f, a mandrel portion 85 m, and a catch element, such as a tailportion 85 t. The finned portion 85 f may include one or more (threeshown) fins extending outward from an outer surface of the mandrelportion 85 m. The dart 85 may include a material having sufficientflexibility to be pumped through the top drive 4. The flexible materialmay be a foamed polymer, such as polyurethane. A diameter of the tailportion 85 t may be greater than a diameter of the mandrel portion 85 mand less than an outer diameter of the finned portion 85 f. A receptaclemay be formed in the tail portion 85 t of the dart 85, and the RFID tag16 may be disposed in the receptacle. The receptacle may be centrallylocated within the dart 85. The RFID tag 16 may be retained in thereceptacle, for example by bonding or interference fit.

The outer diameter of the finned portion 85 f may correspond to, such asequal to, greater than, or substantially greater than, an inner diameterof the tubular string 5 s. The finned portion 85 f may engage thetubular string 5 s as the dart 85 is pumped through the bore thereof forsealing engagement therewith, for centering the dart therein, and formaintaining orientation of the RFID tag 16 relative to the tubularstring 5 s. The orientation may be a parallel relationship between alongitudinal axis of the RFID tag 16 and a longitudinal axis of thetubular string 5 s. The longitudinal axis of the RFID tag 16 may vary by+/−45 degrees from parallel with the longitudinal axis of the tubularstring 5 s to provide for more reliable transmission of command signals.

The seat 87 may be part of a modified control sub 86. The modifiedcontrol sub may be similar to the control sub 6 except for having upperhousing section 89 instead of the housing sections 34 a-d, and havingthe seat 87 instead of the stop 19. The seat 87 may be similar to theantenna plug 38 p. The seat 87 may include a conical upper nozzleportion 87 n, a conical lower diffuser portion 87 d, and a throatportion 87 t connecting the nozzle and diffuser portions. The seat 87may include a relatively stiff and nonconductive material, such as anengineering polymer or fiber reinforced composite.

Referring specifically to FIG. 12A, in preparation of the downholeoperation, a technician may operate the tag carrier launcher 14 via thecontrol console 17. This may provide an additional safety mechanism inembodiments wherein the control console 17 is located remotely from thedrilling rig 1 r. The dart 85 may be released and propelled into thetubular string 5 s by fluid pumped by the mud pump 28. Referringspecifically to FIG. 12B, the dart 85 may travel down the tubular string5 s and into the control sub 6 until a leading fin thereof is caught bythe nozzle portion 87 n. The RFID tag thereby may be aligned with theantenna when the leading fin of the dart is caught by the nozzleportion. The RFID tag 16 may receive the activation signal 50 a from theantenna of the modified control sub 86 and reply by transmitting thecommand signal 50 c thereto. The MCU of the control circuit may operatethe actuator 40 to shift the valve sleeve 47 upward to the openposition. Continued pumping of the fluid against the stopped dart 85 mayincrease pressure 52 in the bore of the tubular string 5 s. The increasein pressure 52 may be detected at the surface by monitoring the pressuregauge 21.

Referring specifically to FIG. 12C, the pressure 52 exerted on the dart85 may increase until a threshold pressure is achieved, thereby passingthe dart through the throat 87 t by compression of the finned portion 85f of the dart, thereby allowing passage of the dart through the throat.Referring specifically to FIG. 12D, once the dart 85 has passed throughthe seat 87, the pressure 52 may decrease and the dart may resumedownward travel through the modified control sub 86 and the circulationsub 7.

Alternatively, the second alternative tag delivery system 90 may be usedwith the first alternative control sub 76 instead of the tag deliverysystem 2.

FIG. 13A illustrates an alternative tag carrier for use with the secondalternative tag delivery system, according to another embodiment of thepresent disclosure. Instead of the tag carrier being the dart 85, thetag carrier may be another type of pump down plug, such as a pig 98. Thepig 98 may be disposed in the canister bore of the tag carrier launcher14. The pig 98 may include a body having an elongated shape, such as ashape resembling an (American) football. The pig body may include amaterial having sufficient flexibility to be pumped through the topdrive 4. The flexible material may be a foamed polymer, such aspolyurethane. A receptacle may be formed in a tail portion 98 t of thepig body and the RFID tag 16 may be disposed in the receptacle. Thereceptacle may be centrally located within the pig 98. The RFID tag 16may be retained in the receptacle by bonding or interference fit.

Alternatively, the pig body may be ellipsoid (i.e., a prolate), egg,capsule, or bullet shaped.

A maximum outer diameter of the pig body may correspond to, such asequal to, slightly greater than, or slightly less than, an innerdiameter of the tubular string 5 s. The pig body may engage the tubularstring 5 s as the pig 98 is pumped through the bore thereof forcentering the pig therein and for maintaining orientation of the RFIDtag 16 relative to the tubular string 5 s. The orientation may be aparallel relationship between a longitudinal axis of the RFID tag 16 anda longitudinal axis of the tubular string 5 s. The longitudinal axis ofthe RFID tag 16 may vary by +/−45 degrees from parallel with thelongitudinal axis of the tubular string 5 s to provide for more reliabletransmission of command signals. The pig body may or may not sealinglyengage the bore of the tubular string 5 s as the pig 98 is pumpedtherethrough. Due to the curved outer surface of the pig 98, the pig maynot be completely stopped upon engagement with the seat 87; however, thepig may be sufficiently slowed to ensure communication between the RFIDtag 16 and the antenna 38.

FIGS. 13B and 14A illustrate a second alternative control sub 99,according to another embodiment of the present disclosure. The secondalternative control sub 99 may include the seat 87, a housing 100, theelectronics package 35, the battery 36, the antenna 38, a mandrel 101,and an actuator 102. The housing 100 may include an upper antennasection 100 u and a lower actuator section 100 b connected togetherlongitudinally, such as by a threaded nut 100 n and threaded couplings,and torsionally, such as by castellations or crenellations. The secondalternative control sub 99 may further include an adapter (not shown)having couplings, such as threaded couplings, formed at longitudinalends thereof for connection to the tubular string 5 s at an upper endthereof and the antenna housing section 92 u at a lower end thereof.

The antenna housing section 100 u may have a pocket formed in an innersurface thereof for receiving the antenna 38 and forming a reservoirchamber 104 therebetween, similar to that of the control sub 6. Theactuator housing section 100 b may have the seat 87 formed in an innersurface thereof and at a top thereof so that the seat is adjacent to theantenna 38. The actuator housing section 100 b may have a pocket formedin an inner surface thereof for receiving the mandrel 101 and themanifold 103. The mandrel 101 may be similar to the control sub mandrel39 and have recesses for receiving the electronics package 35 and thebattery 36. Lead wires may extend between the antenna housing section100 u and the actuator housing section 100 b for connection of theelectronics package 35 and the antenna 38. A hydraulic conduit mayextend between the antenna housing section 100 u and the actuatorhousing section 100 b for fluid communication between the actuator 102and the hydraulic reservoir 104.

The second alternative control sub 99 may be used to operate a secondmodified circulation sub 106 (FIG. 14A). An upper end of the secondmodified circulation sub 106 may be connected to the actuator housingsection 100 b, such as by another threaded nut (not shown) and threadedcouplings, and torsionally, such as by castellations or crenellations.The second alternative control sub 99 may be in fluid communication withthe second modified circulation sub 106, such as by one or more (pairshown) first hydraulic conduits 105 a,b. The second modified circulationsub 106 may be similar to the circulation sub 7 or first alternativecirculation sub 57 except for having hydraulic ports for receiving theexternal hydraulic conduits 105 a,b instead of internal hydraulicpassages.

The actuator 102 may include the electric motor 40 m, the gearbox 40 g,the pump 40 p, a manifold 103, and one or more pressure sensors (notshown). The manifold 103 may include an electric motor 103 m, a gearbox103 g, a motion converter, such as a lead screw 103 s, and a spool valve103 v. The electric motor 103 m may include a stator in electricalcommunication with the motor controller and a rotor in electromagneticcommunication with the stator for being torsionally driven thereby. Thegearbox 103 g may have an input shaft torsionally connected to therotor. The lead screw 103 s may have an input shaft torsionallyconnected to an output shaft of the gearbox 103 g. The spool valve 103 vmay include a shaft connected to an output shaft of the lead screw 103 sfor being longitudinally driven thereby between a first position (FIG.14A) and a second position (FIG. 14B).

The spool valve 103 v may further include a valve member connected tothe shaft and a housing. The spool valve housing may have a port influid communication with the hydraulic reservoir chamber 104 via themandrel hydraulic passage and another port in fluid communication withan outlet of the pump 40 p. The spool valve housing may further have apair of ports in fluid communication with the first hydraulic conduit105 a and another pair of ports in fluid communication with the secondhydraulic conduit 105 b. The valve member may have a pair of passagesfor selectively providing fluid communication between the reservoirchamber 104 and the hydraulic conduit 105 b and between the pump 40 pand the hydraulic conduit 105 a (FIG. 14A), and another pair of passagesfor selectively providing fluid communication between the reservoirchamber 104 and the hydraulic conduit 105 a and between the pump 40 pand the hydraulic conduit 105 a (FIG. 14B).

In the position shown in FIG. 14A, the spool valve 103 v may providefluid communication between the outlet of the pump 40 p and the firsthydraulic conduit 105 a while providing fluid communication between thereservoir chamber 104 and the second hydraulic conduit 105 b. In thesecond position, the spool valve 103 v may provide fluid communicationbetween the outlet of the pump 40 p and the second hydraulic conduit 105b while providing fluid communication between the reservoir chamber 104and first the hydraulic conduit 105 a.

A pressure sensor may be in fluid communication with the reservoirchamber and another pressure sensor may be in fluid communication withan outlet of the pump 40 p and each pressure sensor may be in electricalcommunication with the MCU to indicate when the piston 37 has reachedthe respective upper and lower positions by detecting a correspondingpressure increase at the outlet of the pump.

Alternatively, the manifold 103 may be used with the control sub 6and/or the modified control sub 86 instead of the control valves 44 u,b.

FIG. 14B illustrates another second alternative control sub 107 foroperating a crossover tool 108, according to another embodiment of thepresent disclosure. The second alternative control sub 107 and crossovertool 108 may be used in a reverse liner cementing operation. Duringdeployment of the liner string, the crossover tool 108 may be in aforward bore position. Once the liner string has been deployed to thedesired depth, a first dart 85 may be launched followed by cement slurryand a second dart 85. A quantity of chaser fluid may be pumped followedby a third dart 85. The drilling fluid 20 d may then be pumped to propelthe train down the tubular string 5 s. The MCU of the control sub 107may receive the command signal from the first dart 85 and shift thecrossover tool 108 to a bypass position. Once the cement slurry has beenpumped into the lower formation 27 b, the MCU of the control sub 107 mayreceive the command signal from the second dart 85 and shift thecrossover tool back to the forward bore position. The MCU of the controlsub 107 may ignore the third dart 85 as it may be addressed to a controlsub (not shown) of a liner isolation valve (not shown) for facilitatingexpansion of an expandable liner hanger (not shown). The liner isolationvalve may include a downwardly closing flapper valve and a control subhaving the seat 87 and operable to prop the flapper valve open andrelease the flapper valve in response to receiving a command signal fromthe third dart 85.

Alternatively, the liner isolation valve may be a modification of thealternative circulation sub 57 by omitting the circulation ports 48.Alternatively, the tag delivery system 2 may be used with the secondalternative control subs 99, 107 and/or control sub of the linerisolation valve instead of the alternative tag delivery system 90.

FIG. 15A illustrates a liner deployment assembly 109 having a thirdalternative control sub 110, according to another embodiment of thepresent disclosure. FIG. 15B illustrates operation of the linerdeployment assembly 109. The liner deployment assembly 109 may include asetting tool, such as expander 109 e, the third alternative control sub110, a latch 109 h, and a stinger 109 s. The members 109 e,h,s and 110may be connected to each other, such as by threaded couplings. The linerdeployment assembly 109 may be assembled with the tubular string 5 s toform a tubular string 5 s, 109.

The liner deployment assembly 109 may be used to deploy a tubular string111 into the wellbore 24 until the tubular string 111 is adjacent to thelower formation 27 b. The tubular string 111 may include a liner hanger111 h, a float collar 111 c, joints of liner 111 j, and a shoe (notshown). The liner string members 111 c,h,j may each be connectedtogether, such as by threaded couplings.

The liner hanger 111 h may be an expandable liner hanger and theexpander 109 e may be operable to radially and plastically expand theliner hanger 111 h into engagement with the inner casing string 26. Theexpander 109 e may include an adapter, a mandrel, a piston assembly, anda cone. The piston assembly may include a piston, upper and lowersleeves, a cap, an inlet, and an outlet. The cone may include a body,one or more segments, a base, one or more retainers, a sleeve, a shoe, apusher, and one or more shearable fasteners. The cone may be driventhrough the liner hanger 111 h by the piston. The liner hanger 111 h mayinclude a tubular body made from a ductile material capable ofsustaining plastic deformation, such as a metal or alloy. The linerhanger 111 h may include one or more seals disposed around an outersurface of the body. The liner hanger 111 h may also have a hardmaterial or teeth embedded/formed in one or more of the seals and/or anouter surface of the hanger body for engaging an inner surface of theinner casing string 26 and/or supporting the seals.

Alternatively, the liner hanger may include an anchor and a packoff. Theanchor may be operable to engage the casing and longitudinally supportthe liner string from the casing. The anchor may include slips and acone. The anchor may accommodate rotation of the liner string relativeto the casing, such as by including a bearing. The packoff may beoperable to radially expand into engagement with an inner surface of thecasing, thereby isolating the liner-casing interface. The setting toolmay be operable to set the anchor and packoff independently. The settingtool may be operable to drive the slips onto the cone and compress thepackoff. The anchor may be set before cementing and the packoff may beset after cementing.

The float collar 111 c may include a tubular housing and a check valve.The housing may be tubular, have a bore formed therethrough, and have aprofile for receiving the latch 109 h. The check valve may be disposedin the housing bore and connected to the housing by bonding with adrillable material, such as cement. The check valve may include adrillable material, such as metal or alloy or polymer. The check valvemay include a body and a valve member, such as a flapper, pivotallyconnected to the body and biased toward a closed position, such as by atorsion spring. The flapper may be oriented to allow fluid flow from theliner hanger 111 h into the liner bore and prevent reverse flow from theliner bore into the liner hanger. The flapper may be propped open by thestinger 109 s. Once the stinger 109 s is removed, the flapper may closeto prevent flow of cement slurry from the annulus into the liner bore.

The latch 109 h may longitudinally and torsionally connect the tubularstring 111 to the liner deployment assembly 109. The latch 109 h mayinclude a piston, a stop, a release, a longitudinal fastener, such as acollet, a cap, a case, a spring, one or more sets of one or moreshearable fasteners, an override, a body, a catch, and one or moretorsional fasteners. The latch piston may be fluidly operable to releasefingers of the collet when actuated by a threshold release pressure.Once the liner hanger 111 h has been expanded into engagement with theinner casing string 26 and weight of the liner string 111 is supportedby the liner hanger 111 h, fluid pressure may be increased. The fluidpressure may push the latch piston and fracture the second set ofshearable fasteners, thereby releasing the latch piston. The latchpiston may then move upward toward the collet until the piston abuts abottom of the collet. The latch piston may continue upward movementwhile carrying the collet, case, and cap upward until a bottom of therelease abuts the fingers, thereby pushing the fingers radially inward.During upward movement of the latch piston, the catch may align andenter the recess, thereby forming a downward stop preventingreengagement of the fingers. Movement of the latch piston may continueuntil the cap abuts the stop, thereby ensuring complete disengagement ofthe fingers.

FIGS. 16A-16C illustrate the third alternative control sub 110. Thethird alternative control sub 110 may include a stop 112, a housing 113,an electronics package 114, the battery 36, a mandrel 115, and theactuator 40. The housing 113 may include two or more tubular sectionsconnected to each other, such as by threaded couplings. The housing 113may have couplings, such as threaded couplings, formed at eachlongitudinal end thereof for connection to the latch 109 h at an upperend thereof and the stinger 109 s at a lower end thereof. The housing113 may have a pocket formed therein receiving a sleeve 116 and themandrel 115. The sleeve 116 may replace the antenna 38 and the reservoirchamber may be formed between the housing 113 and the sleeve. Theelectronics package 114 may be similar to the electronics package 35except for the addition of a pressure sensor 114 p thereto. The mandrel115 may be similar to the mandrel 39 except for addition of a port 115 pformed through a wall thereof for placing the pressure sensor 114 p influid communication with a bore of the third alternative control sub110.

The stop 112 may include a seat 112 s, a retainer 112 r, a seat sleeve117 s, a connector sleeve 117 c, and a piston 117 p. The retainer 112 rmay include a metal or alloy, and the seat 112 s may include a flexiblematerial, such as an elastomer or elastomeric copolymer. The retainer112 r may be connected to the housing 113 by entrapment of an upperportion thereof between adjacent sections of the housing. The seat 112 smay be fitted or molded to a lower portion of the retainer 112 r. Theseat 112 s may have cylindrical upper and lower portions and a conicalmid portion extending between the upper and lower portions. The upperportion of the seat 112 s may have a larger inner diameter than thelower portion thereof and the conical portion may converge from theupper portion to the lower portion to accommodate the difference indiameters between the upper and lower portions. The seat 112 s may beoperable to catch a dart 118 (FIG. 17A).

The dart 118 may include a finned seal and a mandrel. The dart mandrelmay include a relatively stiff and drillable material, such as anengineering polymer, fiber reinforced composite, or non-ferrous metal oralloy. The finned seal may include one or more (four shown in FIG. 17A)fins disposed along an outer surface of the mandrel. Each fin mayinclude an elastomer or elastomeric copolymer and be molded or fitted toa gland (not shown) such that the fins may be stacked along the mandrel.The fin glands may also include an engineering polymer or fiberreinforced composite. The mandrel of the dart 118 may have a stackingshoulder (not shown) formed in an outer surface thereof for retainingthe fin glands. The mandrel may also have an enlarged tail for beingcaught by the seat 112 s. A diameter of the tail may be greater than adiameter of the mandrel and less than an outer diameter of the fins. Theouter diameter of the fins may correspond to, such as being equal to,greater than, or substantially greater than, an inner diameter of thetubular string 5 s, 109. The finned seal may engage the tubular string 5s, 109 as the dart 118 is pumped through the bore thereof for sealingengagement therewith.

The inner diameter of the seat upper portion may be greater than thediameter of the dart tail and the inner diameter of the seat lowerportion may be less than the diameter of the dart tail such that thedart tail is caught in the seat conical portion (FIG. 17B) as the dart118 is pumped through the third alternative control sub 110.

A lower end of the seat sleeve 117 s may be connected to an upper end ofthe connector sleeve 117 c, such as by threaded couplings. A lower endof the connector sleeve 117 c may be connected to an upper end of thepiston 117 p, such as by threaded couplings. The piston 117 p may bedisposed in an actuation chamber formed by adjacent sections of thehousing 113 and the piston and sleeves 117 c,s may be longitudinallymovable relative to the seat 112 s between a catch position (FIG. 17A)and a release position (FIG. 17D). The movable unit 117 c,p,s may bestopped in the catch position by engagement of the seat sleeve 117 swith a shoulder formed in an outer surface of the retainer 117 r. Themovable unit 117 c,p,s may be stopped in the release position byengagement of a bottom of the piston with a shoulder formed in an innersurface of the housing 113.

The seat sleeve 117 s may include a stiff material, such as a metal oralloy, and may have a thin walled upper portion and a thick walled lowerportion. The thick walled portion of the seat sleeve seat sleeve 117 smay have an inner diameter fit to an outer diameter of the seat 112 sand the thick walled portion may be aligned with the seat in the catchposition, thereby locking the seat in an unexpanded position. The thinwalled portion of the seat sleeve 117 s may have an inner diametergreater than the outer diameter of the seat 112 s to form a seat chamber112 c therebetween and the thin walled portion may be aligned with theseat in the release position, thereby accommodating expansion (FIG. 17D)of the seat 112 s during passage of the dart 118 therethrough.

The housing sections adjacent to the piston 117 p may carry seals ininner surfaces thereof engaged with the connector sleeve 117 c and alower sleeve portion of the piston to isolate the actuation chamber fromthe bore of the third alternative control sub 110. A shoulder formed inan outer surface of the piston 117 p may be disposed in the actuationchamber and carry a seal in engagement with an inner surface of thehousing 113. The piston shoulder may divide the actuation chamber into acatch portion and a release portion. Each end of the actuation chambermay be in fluid communication with a respective control valve 44 u,b viaa respective hydraulic passage formed in a wall of the housing 113. Eachcontrol valve 44 u,b may also be in fluid communication with an oppositehydraulic passage via a crossover passage.

The control valves 44 u,b may each be electronically actuated, such asby a solenoid, and together may provide selective fluid communicationbetween an outlet of the pump 40 p and the catch and release portions ofthe actuation chamber while providing fluid communication between thereservoir chamber and an alternate one of the catch and release portionsof the actuation chamber. Each control valve actuator may be inelectrical communication with the MCU of the electronics package 114 forcontrol thereby. A pressure sensor may be in fluid communication withthe reservoir chamber and another pressure sensor may be in fluidcommunication with an outlet of the pump 40 p and each pressure sensormay be in electrical communication with the MCU to indicate when thepiston 117 p has reached the respective upper and lower positions bydetecting a corresponding pressure increase at the outlet of the pump 40p.

Alternatively, the third alternative control sub 110 may have themanifold 103 instead of the control valves 44 u,b.

FIGS. 17A-17D illustrate operation of the third alternative control sub110. Referring specifically to FIG. 17A, once the wellbore 24 has beendrilled through the lower formation 27 b to the desired depth and thedrill string 5 retrieved, the tubular string 111 may be assembled andfastened to the liner deployment assembly 109. The tubular string 5 s,109 may be assembled to deploy the tubular string 111 into the lowerformation 27 b. Once the tubular string 111 has been deployed to theappropriate depth, a quantity of cement slurry (not shown) may be pumpedinto the tubular string 5 s followed by a slug of chaser fluid 97 h.Once the cement slurry and chaser fluid 97 h have been pumped, atechnician may operate the tag carrier launcher 14 via the controlconsole 17 and chaser fluid 97 h may be pumped to drive the dart 118 andcement slurry through the tubular string 5 s, 109.

Referring specifically to FIG. 17B, the dart 118 may travel down thetubular string 5 s and into the third alternative control sub 110 untilthe cement slurry flows through the tubular string 111 and into anannulus between the tubular string and the lower formation 27 b and thetail is caught by the seat 112 s. Continued pumping of the chaser fluid97 h against the stopped dart 118 may increase pressure 52 in the boreof the tubular string 5 s. The increase in pressure 52 may be detectedat the surface 25 by monitoring the pressure gauge 21. Pumping maycontinue until a first threshold pressure is achieved to operate theexpander piston, thereby driving the expander cone through theexpandable liner hanger 111 h. Pumping may continue until a secondthreshold pressure is achieved to release the latch 109 h from the floatcollar 111 c.

Referring specifically to FIG. 17C, pressure pulses 119 may betransmitted down the tubular string bore to the pressure sensor 114 p bypumping against the stopped dart 118 and then relieving pressure in thetubular string bore according to a protocol. The MCU may receive thecommand signal from the pulses 119 and shift the seat sleeve 117 s tothe release position.

Referring specifically to FIG. 17D, the tubular string 5 s, 109 may beraised from the tubular string 111, thereby removing the stinger 109 sfrom obstructing closure of the float collar 111 c. The float collar 111c may then close to prevent backflow of the cement slurry into a bore ofthe tubular string 111. Pumping of the chaser fluid 97 h may resumeagainst the stopped dart 118, thereby increasing the pressure 52 andpassing the dart tail through the seat 112 s by expansion thereof,thereby to allow passage of the dart tail through the seat. The dart 118may be ejected into the wellbore 24.

Alternatively, the stop 112 may be used with the control sub 6, thefirst alternative control sub 76, the modified control sub 86, and/orthe second alternative control sub 99 instead of the respective stopsand seats thereof.

FIG. 15C illustrates an accumulator 120 for use with an alternativeliner deployment assembly (not shown), according to another embodimentof the present disclosure. The accumulator 120 may include a housing121, a mandrel 122, a balance piston 123, and a biasing member, such asa compression spring 124. The housing 121 may include two or moretubular sections connected to each other, such as by threaded couplings.The housing 121 may have couplings, such as threaded couplings, formedat each longitudinal end thereof for connection to the latch 109 h at anupper end thereof and the third alternative control sub 110 at a lowerend thereof. The housing 121 may have a pocket formed therein receivingthe mandrel 122 and compression spring 124.

An upper end of the mandrel 122 may be connected to the housing 121,such as by threaded couplings. A chamber may be formed between thehousing 121 and the mandrel 122. The balance piston 123 may be disposedin the chamber and may divide the chamber into an upper annulus portionand a lower accumulation portion. The compression spring 124 may bedisposed in the annulus portion and may have an upper end pressingagainst a spring washer and a lower end pressing against the balancepiston 125, thereby biasing the balance piston toward a lower section ofthe housing 121.

One or more upper ports 125 u may be formed through a wall of thehousing 121 and may provide fluid communication between the annulusportion and an annulus formed between the accumulator 120 and thetubular string 111. A gap 125 g may be formed between a bottom of themandrel 122 and the housing 121, thereby providing fluid communicationbetween the accumulation portion and a bore of the accumulator 120. Thehousing 121 may also have one or more lower ports 125 d formed through awall thereof for equalizing pressure across a joint between adjacenthousing sections.

The alternative liner deployment assembly may be similar to the linerdeployment assembly 109 except for having a modified expander (notshown). The modified expander may be similar to the expander 109 eexcept for the addition of a liner isolation valve, a piston proppingopen the isolation valve, and a crossover valve. The third alternativecontrol sub 110 may be used to activate the prop piston to release theisolation valve. Once the isolation valve has closed, pressure exertedthereon may move the isolation valve downward to open the crossovervalve. The presence of the accumulator 120 may prevent unintentionalhydraulic locking from obstructing downward movement of the isolationvalve.

FIGS. 18A and 18B illustrate a fourth alternative control sub 126,according to another embodiment of the present disclosure. The fourthalternative control sub 126 may include a stop 127, a housing 128, theelectronics package 114, the battery 36, the antenna 38, a mandrel 129,and the actuator 102. The housing 128 may include a plurality of tubularsections connected together longitudinally, such as by a threaded nutand threaded couplings, and torsionally, such as by castellations orcrenellations. The fourth alternative control sub 126 may furtherinclude an adapter (not shown) having couplings, such as threadedcouplings, formed at longitudinal ends thereof for connection to thetubular string 5 s at an upper end thereof and an upper section of thehousing 128 at a lower end thereof.

The fourth alternative control sub 126 may be used to operate the secondmodified circulation sub 106 and the crossover tool 108. An upper end ofthe second modified circulation sub 106 may be connected to a lowersection of the housing 128, such as by another threaded nut (not shown)and threaded couplings, and torsionally, such as by castellations orcrenellations, and an upper end of the crossover tool 108 may beconnected to a lower end of the second modified circulation sub 106,such as by another threaded nut (not shown) and threaded couplings, andtorsionally, such as by castellations or crenellations. The fourthalternative control sub 126 may be in fluid communication with thesecond modified circulation sub 106, such as by a first pair ofhydraulic conduits (not shown) and may be in fluid communication withthe crossover tool 108, such as by a second pair of hydraulic conduits(not shown). The actuator 102 may include manifolds 103 for each of thestop 127, second modified circulation sub 106, and the crossover tool108 or a single manifold for all three.

The upper housing section may have a pocket formed in an inner surfacethereof for receiving the sleeve 116 and forming the reservoir chamber104 therebetween. An actuator section of the housing 128 may have apocket formed in an inner surface thereof for receiving the mandrel 129and the manifold 103. The mandrel 129 may be similar to the mandrel 101except for addition of the port 115 p formed through a wall thereof forplacing the pressure sensor 114 p in fluid communication with a bore ofthe fourth alternative control sub 126. The mandrel 129 may haverecesses for receiving the electronics package 114 and the battery 36. Ahydraulic conduit may extend between the upper housing section and theactuator housing section for fluid communication between the actuator102 and the hydraulic reservoir 104. The antenna 38 may be located alongan inner surface of a body of the manifold 103 and adjacent to the boreof the fourth alternative control sub 126. Lead wires may extend betweenthe manifold 103 and mandrel 129 for connection of the electronicspackage 114 and the antenna 38.

The stop 127 may include a segmented seat 127 s, the seat sleeve 117 s,the connector sleeve 117 c, and the piston 117 p. The segmented seat 127s may include a metal or alloy. The segmented seat 127 s may be a collethaving an upper base portion and fingers extending from the base portionto a lower end thereof. The collet base may have a threaded socketformed in an upper end thereof for connection to a threaded shoulderformed in an adjacent section of the housing 128. The segmented seat 127s may be longitudinally and/or radially movable between an expandedposition (not shown) and a contracted position (shown) by interactionwith the seat sleeve 117 s. Each collet finger may have a lug formed ata lower end thereof. The collet fingers may be cantilevered from thecollet base and have a stiffness urging the lugs toward the expandedposition. The seat 127 s may be operable to catch a dart 130 (FIG. 18C).

The dart 130 may include a finned seal and a mandrel. The dart mandrelmay include a relatively stiff and nonconductive material, such as anengineering polymer or fiber reinforced composite. The finned seal mayinclude one or more fins disposed along an outer surface of the mandrel.Each fin may include an elastomer or elastomeric copolymer and be moldedor fitted to a gland (not shown) such that the fins may be stacked alongthe mandrel. The fin glands may also include an engineering polymer orfiber reinforced composite. The mandrel of the dart 130 may have astacking shoulder (not shown) formed in an outer surface thereof forretaining the fin glands. The mandrel may also have an enlarged head forbeing caught by the seat 127 s. A diameter of the head may be greaterthan a diameter of the mandrel and less than an outer diameter of thefins.

A receptacle may be formed in a tail portion of the dart mandrel and theRFID tag 16 may be disposed in the receptacle. The receptacle may becentrally located within the dart 130. The RFID tag 16 may be retainedin the receptacle by bonding or interference fit. The outer diameter ofthe finned seal may correspond to, such as equal to, greater than, orsubstantially greater than, an inner diameter of the tubular string 5 s,109. The finned seal may engage the tubular string 5 s, 109 as the dart130 is pumped through the bore thereof for sealing engagement therewith,for centering the dart therein, and for maintaining orientation of theRFID tag 16 relative to the tubular string. The orientation may be aparallel relationship between a longitudinal axis of the RFID tag 16 anda longitudinal axis of the tubular string 5 s, 109. The longitudinalaxis of the RFID tag 16 may vary by +/−45 degrees from parallel with thelongitudinal axis of the tubular string 5 s to provide for more reliabletransmission of command signals. A length of the dart 130 may correspondto a distance between the seat 127 s and the antenna 38 such that theRFID tag 16 is aligned with the antenna 38 when the dart is caught inthe seat.

An inner diameter of the base and fingers of the seat 127 s may begreater than the diameter of the dart head and the (retracted) innerdiameter of the seat lugs may be less than the diameter of the dart headsuch that the dart head is caught by the seat lugs (FIG. 18C) as thedart 130 is pumped through the fourth alternative control sub 126.

The piston 117 p may be disposed in an actuation chamber formed byadjacent sections of the housing 128 and the piston and sleeves 117 c,smay be longitudinally movable relative to the seat 127 s between thecatch position and a release position (not shown). The movable unit 117c,p,s may be stopped in the catch position by engagement of the seatsleeve 117 s with a shoulder formed in an outer surface of the seat 127s. The movable unit 117 c,p,s may be stopped in the release position byengagement of a bottom of the piston 117 p with a shoulder formed in aninner surface of the housing 128.

The thick walled portion of the seat sleeve seat sleeve 117 s may havean inner diameter fit to an outer diameter of the lugs of the seat 127 sand the thick walled portion may be aligned with the seat lugs in thecatch position, thereby locking the seat in a contracted position. Thethin walled portion of the seat sleeve 117 s may have an inner diametergreater than the (contracted) outer diameter of the seat lugs to form aseat chamber therebetween and the thin walled portion may be alignedwith the seat lugs in the release position, thereby accommodatingexpansion of the seat 127 s during passage of the dart 130 therethrough.

The housing sections adjacent to the piston 117 p may carry seals ininner surfaces thereof engaged with the connector sleeve 117 c and alower sleeve portion of the piston to isolate the actuation chamber fromthe bore of the fourth alternative control sub 126. A shoulder formed inan outer surface of the piston 117 p may be disposed in the actuationchamber and carry a seal in engagement with an inner surface of thehousing 128. The piston shoulder may divide the actuation chamber into acatch portion and a release portion. Each end of the actuation chambermay be in fluid communication with the manifold 103 via a respectivehydraulic conduit 131 a,b (third pair).

FIG. 18C illustrates delivery of the RFID tag 16 to the fourthalternative control sub 126. The fourth alternative control sub 126,second modified circulation sub 106, crossover tool 108, and thirdalternative control sub 110 may be used in a reverse liner reaming andcementing operation. For reverse reaming of the liner string, the secondmodified circulation sub 106 may be in a first position having the borevalve open and the circulation ports closed and the crossover tool 108may be in a reverse bore position. After reverse reaming of the linerstring, heating fluid may be placed in the annulus between the linerstring and the wellbore. Pressure pulses 119 addressed to both thesecond modified circulation sub 106 and the crossover tool 108 may besent down the bore of the tubular string 5 s. The MCU of the fourthalternative control sub 126 may receive the command signal from thepressure pulses 119 and shift the second modified circulation sub 106 toa second position having the bore valve closed and circulation portsopen and shift the crossover tool 108 to a forward bore position. Oncethe second modified circulation sub 106 and the crossover tool 108 haveshifted, forward circulation may commence and be maintained while theheating fluid heats the lower formation.

Once the lower formation has been heated, a first dart 130 may belaunched followed by cement slurry and a second dart 130. A quantity ofchaser fluid may be pumped followed by a third dart 118. The drillingfluid 20 d may then be pumped to propel the fluid train down the tubularstring 5 s. The MCU of the fourth alternative control sub 126 mayreceive the command signal from the first dart 130 and shift the secondmodified circulation sub 106 back to the first position and shift thecrossover tool 108 to a bypass position. Once the cement slurry has beenpumped into the lower formation 27 b, the MCU of the fourth alternativecontrol sub 126 may receive the command signal from the second dart 130and shift the crossover tool 108 back to the forward bore position. TheMCU of the fourth alternative control sub 126 may leave the stop 127 inthe release position after the second dart 130 such that the third dart85 passes freely through the seat 127 s and lands in the thirdalternative control sub 110 for setting of the liner hanger.

Alternatively, modified versions of the second alternative control subs99, 107 (and associated darts 85) may be used reverse liner reaming andcementing operation instead of the fourth alternative control sub 126.The modification may be that the electronics package 35 is replaced withthe electronics package 114 and the port 115 p added to the mandrels101.

Alternatively, the collet seat 127 s may be used with the thirdalternative control sub 110 instead of the flexible seat 112 s.Alternatively, a modified collet seat may be used with the control sub6, the first alternative control sub 76, the modified control sub 86,and/or the second alternative control sub 99 instead of the seatsthereof. The modified collet seat may be naturally biased toward thecontracted position. Alternatively the seat 127 s may include anothertype of fastener, such as dogs, instead of the fingers and lugs and thedogs may or may not be spring loaded.

FIG. 19 illustrates a method 200 of using a tag delivery system 2. Atstep 210, an RFID tag 16 is programmed. RFID tags 16 may be programmedas a final step in the manufacturing process, prior to shipping. RFIDtags 16 may be programmed upon receipt at the drilling site, and thenstored prior to use. However, since programming includes commands to bedelivered to specific tools, and the types of commands may vary by tooland by ad hoc operational demands, prior programming may require preciseinventory maintenance so that correctly-programmed RFID tags 16 areutilized at any given time. In some embodiments, an RFID tag 16 may beprogrammed immediately prior to the loading of a tag carrier into a tagcarrier launcher 14. Thus control progresses along path A to step 220,wherein the tag carrier is launched.

Alternatively, in some embodiments, an RFID tag 16 may be programmedsubsequently to the loading of a tag carrier in a tag carrier launcher14. For example, either at the tag carrier launcher 14 or at a portionof the tubular string 5 s downhole from the tag carrier launcher 14, atag reader/programmer may program the RFID tag 16. This may beadvantageous to allow bulk loading of tag carriers without regard toprecise inventory control. The tag reader/programmer may be controlledfrom the console 17. Thus, a tag carrier is launched at step 220, withcontrol progressing along path B to step 210, wherein the RFID tag 16 isprogrammed.

Once the RFID tag 16 is programmed and the tag carrier is launched, anoptional step 230 may occur to confirm the RFID 16 tag programmingand/or the tag carrier launch. For example, at a portion of the tubularstring 5 s downhole from the tag carrier launcher 14, a tag reader maydetect passage of the tag carrier and confirm programming of the RFIDtag 16. In some embodiments, a launcher adapter may include anelectronics package and antenna for reading the RFID tag 16 as the tagcarrier is pumped therethrough for confirmation of launching of the dartand transmission of a confirmation signal to the control console 17. Inthe event of failure of the programming or the launch, control mayreturn to repeat steps 210/220. This may be advantageous for continuouspumping operations.

With the tag carrier traveling through the tubular string 5 s, at step240, a RFID tag 16 is positioned in the vicinity of an antenna 38 of acontrol sub 6 for transmission of a command signal. Positioning mayinclude aligning the orientation of the longitudinal axis of the RFIDtag 16 with the antenna 38, slowing the speed of the tag carrier, and/orcentralizing or moving the RFID tag 16 radially within the tubularstring 5 s. Thus, positioning may include catching the tag carrier witha stop.

At step 250, the RFID tag 16 transmits a command signal to the antenna38 of the control sub 6. Optionally, the RFID tag 16 may be actuated bythe control sub 6 at step 245. Actuation may include sending power, anactivation signal, or both. The activation signal may include toolidentification information. The RFID tag 16 may respond to the actuationby either transmitting a command signal—if the tool is the appropriatetool for that RFID tag 16—or the RFID tag 16 may respond by transmittinga null signal—if the tool is not the appropriate tool for that RFID tag16. Alternatively, the RFID tag 16 may transmit the same command signalto each tool, and each control sub 6 may determine whether the commandsignal is appropriate for that tool.

At optional step 260, the tag carrier may remain in the position fromstep 240 240 (for example, either caught by the stop, or slowed in thetubular string 5s) until the tool provides a response. The response maybe indicative that the tool received the command signal and actedappropriately. The response may be indicative that the tool either didnot receive the command signal or did not act appropriately. Theresponse may be inferred by an elapsed period of time. An exampleresponse may be that the fluid pressure in the tubular string 5 sincreases by a certain amount or to a certain threshold over adesignated period of time. Such response may be detected at the surface.

Following either transmitting a command to the tool at step 250 orwaiting for a tool response at 260, the tag carrier continues downholeat step 270. For example, once a pressure signal is received at thesurface indicative that the tool received the command signal and actedappropriately, pumping pressure is increased to dislodge the tag carrierfrom the position from step 240 (e.g., pass the tag carrier through theseat).

In one or more of the embodiments described herein, the stop comprises aseat.

In one or more of the embodiments described herein, the tag carriercomprises a dart, the stop comprises a seat, the seat comprises aflexible material, the stop is operated by increased fluid pressuredriving the dart through the seat, and a body of the dart comprises astiff material.

In one or more of the embodiments described herein, the dart bodycomprises a mandrel and a ball stud for being caught in the seat, thedart further comprises one or more fins stacked along the mandrel, theball stud is connected to a trailing end of the mandrel, and the radiofrequency identification tag is disposed in a nose of the mandrel.

In one or more of the embodiments described herein, the flexiblematerial is an elastomer or elastomeric copolymer, and the stiffmaterial is an engineering polymer or fiber reinforced composite.

In one or more of the embodiments described herein, the control subfurther comprises a tubular housing having couplings at eachlongitudinal end thereof, and one of the couplings is for mating with acoupling of the downhole tool.

In one or more of the embodiments described herein, the control subfurther comprises: an electronics package in electrical communicationwith the antenna; a battery in electrical communication with theelectronics package; an actuator in electrical communication with theelectronics package, a reservoir of hydraulic fluid; and a piston forconnection to the downhole tool; the actuator is linkable with thedownhole tool for operation thereof and the actuator comprises: anelectric motor for driving a pump; and the pump for supplying thehydraulic fluid from the reservoir to the piston.

In one or more of the embodiments described herein, the actuator furthercomprises: a spool valve movable between a first position and a secondposition; and an electric motor in electrical communication with theelectronics package for moving the spool valve between the positions,the spool valve provides fluid communication between the pump and afirst face of the piston while providing fluid communication between thehydraulic reservoir and a second face of the piston in the firstposition, and the spool valve provides fluid communication between thepump and the second face of the piston while providing fluidcommunication between the hydraulic reservoir and the first face of thepiston in the second position.

In one or more of the embodiments described herein, the control subfurther comprises: an electronics package in electrical communicationwith the antenna; a battery in electrical communication with theelectronics package; an actuator in electrical communication with theelectronics package; a reservoir of hydraulic fluid; a piston forengagement with a piston of the downhole tool; and a return spring forbiasing the actuator piston into engagement with the piston of thedownhole tool, the actuator is linkable with the downhole tool foroperation thereof; and the actuator further comprises a control valvefor selectively providing or blocking fluid communication between thepiston and the reservoir.

In one or more of the embodiments described herein, the downhole tool isa circulation sub and comprises: a bore extending therethrough a tubularhousing; one or more circulation ports formed through a wall of thehousing; and a valve sleeve for selectively opening and closing theports.

In one or more of the embodiments described herein, the downhole toolfurther comprises a bore valve for selectively opening and closing thebore of the downhole tool, and a valve member of the bore valve isconnected to the valve sleeve below the circulation ports such that thebore valve is closed when the circulation ports are open and the borevalve is open when the circulation ports are closed.

In one or more of the embodiments described herein, the control subfurther comprises an electronics package in electrical communicationwith the antenna; a battery in electrical communication with theelectronics package; an actuator in electrical communication with theelectronics package; and an arrival sensor in electrical communicationwith the electronics package; the actuator is linkable with the downholetool for operation thereof; and the arrival sensor links the stop to thehousing for closing a circuit in response to catching of the tagcarrier.

In one or more of the embodiments described herein, the control subfurther comprises: an electronics package in electrical communicationwith the antenna; a battery in electrical communication with theelectronics package; an actuator in electrical communication with theelectronics package; and an arrival sensor in electrical communicationwith the electronics package; the actuator is linkable with the downholetool for operation thereof; the arrival sensor comprises: a first partof an electrical circuit disposed in the stop; and a second part of anelectrical circuit carried by the tag carrier, and the electricalcircuit is closed by catching of the tag carrier.

In one or more of the embodiments described herein, the system furtherincludes a launcher for connecting to a top of a drill pipe string andreleasing the tag carrier into the drill pipe string; and a swivel forconnecting the launcher to a quill of a top drive.

In one or more of the embodiments described herein, the stop comprises aseat and a seat sleeve having a thick walled portion and a thin walledportion, the thick walled portion has an inner diameter fit to an outerdiameter of the seat, the thin walled portion has an inner diametergreater than the outer diameter of the seat to form a seat chambertherebetween, and the seat sleeve is movable between a catch positionand a release position.

In one or more of the embodiments described herein, the stop furthercomprises a piston for moving the seat sleeve between the positions, thecontrol sub further comprises: an electronics package in electricalcommunication with the antenna; a battery in electrical communicationwith the electronics package; an actuator in electrical communicationwith the electronics package, and a reservoir of hydraulic fluid, andthe actuator comprises: an electric motor for driving a pump; and thepump for supplying the hydraulic fluid from the reservoir to the piston.

In one or more of the embodiments described herein, the radio frequencyidentification tag is centrally located within the tag carrier.

In one or more of the embodiments described herein, the tubular stringis a drill string, the downhole tool is a circulation sub comprising aport valve, the method further comprises drilling a wellbore using thedrill string, the port valve is closed during drilling, the control subopens the port valve in response to receiving the command signal, andthe method further comprises cleaning out the wellbore using the openport valve.

In one or more of the embodiments described herein, the tubular stringis a work string, the work string further comprises a drill pipe string,the method further comprises: running a second tubular string into awellbore using the work string; and pumping cement slurry into the drillpipe string adjacent to the tag carrier, and the cement slurry is pumpedthrough the drill pipe string with the tag carrier.

In one or more of the embodiments described herein, the cement slurry ispumped behind the tag carrier, the downhole tool is a circulation subcomprising a port valve and a bore valve, the port valve is open and thebore valve is closed during pumping, thereby diverting fluid displacedby the tag carrier up an inner annulus formed between the tubular stringand the work string, and the control sub closes the port valve and opensthe bore valve in response to receiving the command signal.

In one or more of the embodiments described herein, closing of the portvalve and opening of the bore valve forces the cement slurry to flow upan outer annulus formed between the tubular string and the wellbore.

In one or more of the embodiments described herein, the second tubularstring comprises a float collar, the work string extends into the floatcollar and props open the float collar, and the method further comprisesremoving the work string from the float collar, thereby allowing thefloat collar to close.

In one or more of the embodiments described herein, the wellbore is asubsea wellbore, and the second tubular string is a surface casingstring.

In one or more of the embodiments described herein, the stop comprises aseat, a seat sleeve is engaged with the seat while the tag carrier iscaught in the seat, and an actuator of the control sub disengages theseat sleeve from the seat in response to the command signal.

In one embodiment, a system for operating a downhole tool includes apump down plug comprising a flexible material; a radio frequencyidentification tag coupled with the pump down plug; and a control subhaving a bore extending therethrough and comprising: an antenna locatedadjacent to the bore; and a stop for engagement with the pump down plug,wherein: the radio frequency identification tag is coupled with the pumpdown plug in relation to the stop and the antenna such that the radiofrequency identification tag is aligned with the antenna when the pumpdown plug is engaged with the stop.

In one or more of the embodiments described herein, engagement of thestop with the pump down plug at least sufficiently slows the pump downplug to ensure communication between the radio frequency identificationtag and the antenna.

In one or more of the embodiments described herein, the pump down plugis a dart.

In one or more of the embodiments described herein, the dart comprises afinned portion, a mandrel portion, and a tail portion, and the radiofrequency identification tag is disposed in the tail portion.

In one or more of the embodiments described herein, the flexiblematerial is a foamed elastomer, the stop comprises a stiff material, andthe stiff material is an engineering polymer or fiber reinforcedcomposite.

In one or more of the embodiments described herein, the system furtherincludes a launcher for assembly as part of a supply line connecting amud pump to a top drive and for releasing the pump down plug into thesupply line.

In one or more of the embodiments described herein, the pump down plugis a pig.

In one embodiment, a system for operating a downhole tool includes a tagcarrier; a control sub having a bore extending therethrough andcomprising: an electronics package; a pressure sensor in fluidcommunication with the bore and in electrical communication with theelectronics package for detecting a pressure pulse in the bore; and astop comprising: a seat for catching the tag carrier; and a seat sleevehaving a thick walled portion and a thin walled portion, wherein: thethick walled portion has an inner diameter fit to an outer diameter ofthe seat, the thin walled portion has an inner diameter greater than theouter diameter of the seat to form a seat chamber therebetween, and theseat sleeve is movable between a catch position and a release position.

In one or more of the embodiments described herein, the seat comprises aflexible material.

In one or more of the embodiments described herein, the seat is a collethaving a base portion, fingers extending from the base portion, and lugsformed at ends of the fingers.

In one or more of the embodiments described herein, the stop furthercomprises a piston for moving the seat sleeve between the positions, thecontrol sub further comprises: a battery in electrical communicationwith the electronics package; an actuator in electrical communicationwith the electronics package, and a reservoir of hydraulic fluid, andthe actuator comprises: an electric motor for driving a pump; and thepump for supplying the hydraulic fluid from the reservoir to the piston.

In one or more of the embodiments described herein, the system furtherincludes a latch connected to the control sub; a liner hanger fastenedto the latch; and a setting tool connected to the latch and operable toset the liner hanger in response to fluid pressure exerted on the caughttag carrier.

In one or more of the embodiments described herein, the system furtherincludes an accumulator connected to the control sub; a latch connectedto the accumulator; an expandable liner hanger fastened to the latch;and an expander connected to the latch, wherein fluid pressure exertedon the caught tag carrier and the accumulator facilitate operation ofthe expander.

While the foregoing is directed to embodiments of the presentdisclosure, other and further embodiments of the disclosure may bedevised without departing from the basic scope thereof, and the scope ofthe invention is determined by the claims that follow.

1. A command signal transmission system, comprising: a tag carrier foruse in a tubular string and comprising: a centering portion having anouter diameter corresponding to an inner diameter of the tubular string;and a RFID tag having a longitudinal axis, wherein, when the tag carrieris used in the tubular string, the longitudinal axis of the RFID tag isoriented parallel to a longitudinal axis of the tubular string; and acontrol sub having a bore extending therethrough, the control subcomprising: an antenna located adjacent to the bore; and a stop forcatching the tag carrier, wherein: when the tag carrier is caught in thestop, the longitudinal axis of the RFID tag is aligned with the antenna,and the stop is operable to allow passage of the tag carrier through thestop after the tag carrier is caught by the stop.
 2. The system of claim1, wherein the centering portion comprises at least one of a fin, afinned portion, a finned seal, a pig body, and a flexible material. 3.The system of claim 1, wherein the outer diameter of the centeringportion comprises at least one of a non-compressed diameter of a finnedportion and a maximum outer diameter of a pig body.
 4. The system ofclaim 1, wherein the outer diameter of the centering portion is greaterthan or equal to the inner diameter of the tubular string.
 5. The systemof claim 1, wherein, when the tag carrier is used in the tubular string,the centering portion sealingly engages the tubular string.
 6. Thesystem of claim 1, wherein, when the tag carrier is used in the tubularstring, the longitudinal axis of the RFID tag varies by +/−45 degreesfrom parallel with the longitudinal axis of the tubular string.
 7. Thesystem of claim 1, wherein the tag carrier comprises a pig, and a shapeof the pig comprises at least one of an elongated shape, an Americanfootball, an ellipsoid, a prolate, an egg, a capsule, and a bullet. 8.The system of claim 1, further comprising a tag carrier launcher and atag reader/programmer.
 9. The system of claim 8, wherein the tagreader/programmer is downhole from the tag carrier launcher.
 10. Thesystem of claim 1, wherein the RFID tag is centrally located within thetag carrier.
 11. A method of transmitting a command signal, comprising:launching a tag carrier carrying a RFID tag into a tubular string,wherein the tubular string comprises a control sub; pumping the tagcarrier down the tubular string; positioning the RFID tag in a vicinityof an antenna of the control sub, wherein the positioning comprises atleast one of: centralizing the RFID tag within the tubular string;moving the RFID tag radially within the tubular string; and catching thetag carrier with a stop; and transmitting the command signal from theRFID tag to the antenna while the RFID tag is positioned in the vicinityof the antenna.
 12. The method of claim 11, wherein the positioningfurther comprises aligning the RFID tag with the antenna.
 13. The methodof claim 11, further comprising programming the RFID tag.
 14. The methodof claim 13, further comprising loading the tag carrier into a tagcarrier launcher prior to the launching the tag carrier, wherein theprogramming the RFID tag occurs after the loading the tag carrier andbefore the launching the tag carrier.
 15. The method of claim 13,further comprising, after launching the tag carrier, confirming theprogramming of the RFID tag.
 16. The method of claim 15, furthercomprising, after confirming the programming of the RFID tag, repeatingthe launching and programming steps with a second tag carrier.
 17. Amethod of transmitting a command signal, comprising: loading a tagcarrier carrying a RFID tag into a tag carrier launcher; launching thetag carrier into a tubular string, wherein the tubular string comprisesan antenna; programming the RFID tag after loading the tag carrier andbefore launching the tag carrier; pumping the tag carrier down thetubular string; and positioning the RFID tag in a vicinity of theantenna.
 18. The method of claim 17, further comprising, after launchingthe tag carrier, confirming the programming of the RFID tag.
 19. Themethod of claim 18, further comprising, after confirming the programmingof the RFID tag, repeating the launching and programming steps with asecond tag carrier.
 20. The method of claim 17, further comprisingtransmitting the command signal from the RFID tag to the antenna whilethe RFID tag is positioned in the vicinity of the antenna.